I would love to know how OP came across this email nearly 20 years after the fact
SoftTalker•Jul 12, 2026
It's one of Theo's more famous dismissals/takedowns.
DonHopkins•Jul 12, 2026
Some people keep classic flames alive to deploy in times of need. Theo's good, but he can't hold a candle to the late Marc Cripsin railing about emacs line-mode-visual. Grr.
>What mindless cretin thought that it should be a good idea to make
line-move-visual be the default in emacs 23?
I just found out about this charming "improvement" in the worst possible
way. Investigation determined that a "routine" software update had just
installed emacs 23 and gave me this "improvement".
>People wonder why everybody hasn't dumped proprietary desktop software.
This is an example why. Emacs' line behavior has well over 30 years of
history, and some bagbiter goes and changes it BY DEFAULT.
>Add all the cute new features you want. But leave the goddamn defaults
alone.
>If you want to have your own playpen where you twiddle defaults to your
hearts content, have at it. But don't pretend that you produce software
for a production environment, and stop telling the Linux distributions
that they should "upgrade" to your "improved" versions. People doing real
work depend upon those distributions.
>It does no good to say "read the release notes" when the affected users
don't get the release notes and don't even know that a new release
happened. It is also unreasonable to expect users to subscribe to every
obscure newsgroup, forum, and wiki to hear about changes that will turn
their expectations upside down.
>Yes, I fixed my .emacs file. And I'm putting in the same change to all
the .emacs files on all the dozens of other machines I use, even though
they still have emacs 22, because otherwise this unpleasant surprise will
repeat itself over and over again.
>Grr.
>From: Mark Crispin, To: comp.lang.emacs
>They made the wrong decision. Changes to default behavior are a bad idea.
Changes to default behavior of the most basic functionality are an
extremely bad idea.
>I don't care if M-X fart-noisily-with-spray changes its default scent from
skunk to lemon. But I damn well do care about the most basic operations:
all CTRL single letter and ESC single letter. After 33+ years of using
emacs, I expect these to be reliable and not suddenly change.
>I wasted hours trying to figure out what the hell was wrong with my file,
or my terminal emulator window, or my system. The fact that the problem
went away on a different system added further confusion. It was only when
I did ESC <n> CTRL/N and saw that it moved me the wrong number of lines,
but only on one system, that I realized that emacs changed. And that's
when I did ESC X describe-key CTRL/N and read about line-mode-visual,
although it did not mention that this was now the default.
>Surprise. Grr.
em-bee•Jul 12, 2026
i don't know that crispin rant sounds pretty reasonable to me. it's not insulting and the argument is coherent. he has a point.
DonHopkins•Jul 12, 2026
Theo's rant about what an hypocritical idiot ESR is also sounds pretty reasonable to me: he has a point.
ESR's free to make ridiculous laws that aren't true, but blaming it on Linus was a dick mode.
porridgeraisin•Jul 12, 2026
Another classic. About the X11 selection mechanism
Imagine being so hard you're labelled as "difficult" by no other but Linus Torvalds
TylerE•Jul 12, 2026
I mean, Torvalds has called basically every person on earth an asshole at some point, hasn’t he? He’s the opposite of being sparing with critisicism, and frankly has historically often used his bully pulpit to do it.
pdpi•Jul 12, 2026
My read on Torvalds is that, coming from him, "asshole" is a much lesser criticism than "difficult".
sidkshatriya•Jul 12, 2026
Thanks for sharing the forbes link. From the link:
"De Raadt says BSD could have become the world's most popular open source operating system, except that a lawsuit over BSD scared away developers, who went off to work on Linux and stayed there even after BSD was deemed legal."
There is some truth to that. And who knows where BSDs might have been if the lawsuit never happened.
However, I think Linux has always has and till today has better leadership, and management compared to OpenBSD.
I also think GPLv2 was another good that happened to Linux. It just creates an irresistible force to contribute back. With *BSD, a company might contribute back or it may not.
scythe•Jul 12, 2026
It's hard to blame OpenBSD's management when there are three other BSDs. You didn't have to work with Theo de Raadt to work on BSD. But while the lawsuit may have been the catalyst, the game was really over when GNOME took off. BSD was sort of an equal target under KDE, but GNOME prioritized Linux pretty hard and had a lot of fans. At that point pretty much everyone making interesting desktop stuff went to Linux and never looked back. Which is not solely a license issue; you can definitely release GPL software for FreeBSD, but the "license war" culture (to the extent it really existed) may have been an issue.
And I guess I do think that FreeBSD had a saner organization pattern than the sort of haphazard ecosystem of projects that grew up around GNU and Linux. Maybe the chaos was necessary for growth, but it still seems to be a hurdle for new Linux users in the current day.
em-bee•Jul 12, 2026
i think what the chaos did was enable more individual contributors. you didn't have to join the BSD team to get a core OS tool accepted into the system. anyone could just mix and match the tools and apps they liked. it's not that BSD prevented that but that they just didn't invite it. you can create your own spin of a distribution and if it gets enough users and contributors it gets accepted as an official version. there is even a debian variant using a BSD kernel. try making a official BSD spin using GNU coreutils.
znpy•Jul 12, 2026
> there is even a debian variant using a BSD kernel.
> The development of Debian GNU/kFreeBSD has officially terminated as of July 2023 due to the lack of interest and volunteers. You may find the official announcement here[1]
GNOME prioritises Linux now but it shipped with Solaris from 2003 onwards and Sun contributed accessibility features around that time.
znpy•Jul 12, 2026
> BSD was sort of an equal target under KDE, but GNOME prioritized Linux pretty hard and had a lot of fans.
oh boy its' much worse than that: KDE/GNOME were already largely precarious before that.
The whole Xorg thing was really dependant on gpu drivers and the story between linux gpu drivers and *bsd gpu drivers was so much different. Having the BSDs be fairly different didn't really help (eg: only FreeBSD had official nvidia drivers, albeit proprietary).
Gnome did take a lot of backlash and Gnome essentially became a meme at some point ("what's the use case for that?")
Gnome did take a strong dependency on systemd (both gnome and systemd are developed by Red Hat, btw).
And Gnome also did push a lot for wayland (that wasn't implemented on the various BSDs for a long time).
I haven't checked in a while, but I think Gnome is wayland-only nowadays ?
Ultimately, the real issue with KDE/GNOME and the BSDs is that the BSDs are largely irrelevant and essentially only relevant for some specific use-cases where desktop usage is not involved.
mmh0000•Jul 12, 2026
Ha! That’s some rose-colored-glasses view of BSD history.
The lawsuit didn’t help. But the BSD developers shot themselves in the foot when they refused to support x86, referring to it as a “toy”.
It wasn't until Linux came along and started eating up all of BSD's user base that they freaked out and decided x86 support might be a good idea. But by then it was too late.
znpy•Jul 12, 2026
I go back to take a look at the BSDs every now and then and frankly it really looks like that mindset has stayed, somehow.
Generally speaking the BSDs seems really fork-a-phobic and it kinda shows given how little dynamism is there in the development those systems.
Even the Solaris derivatives have a faster tempo.
ErroneousBosh•Jul 12, 2026
> But the BSD developers shot themselves in the foot when they refused to support x86, referring to it as a “toy”.
When was that? Presumably wwaaaaaaaay before 386BSD was a thing right?
mmh0000•Jul 12, 2026
386BSD came out about the right time, but as noted, development was slow, and the original author abandoned it pretty quickly while at the same time Linux was actively gaining traction and growing rapidly.
Quotes below:
"No one else saw the 386 as interesting. Berkeley had a myopic attitude toward PCs. They were just toys. No one would support Intel." — Jordan Hubbard [1]
---
Jolitz's project, of course, found many people on the Net who didn't think it was just a toy. Once he put the source code on the Net, a bloom of enthusiasm spread through the universities and waystations of the world. People wanted to experiment with a high-grade OS and most could only afford relatively cheap hardware like the 386. Sure, places like Berkeley could get the government grant money and the big corporate donations, but 2,000-plus other schools were stuck waiting. Jolitz's version of 386BSD struck a chord.
While news traveled quickly to some corners, it didn't reach Finland. Network Release 2 came in June 1991, right around the same time that Linus Torvalds was poking around looking for a high-grade OS to use in experiments. Jolitz's 386BSD came out about six months later as Torvalds began to dig into creating the OS he would later call Linux. Soon afterward, Jolitz lost interest in the project and let it lie, but others came along. In fact, two groups called NetBSD and FreeBSD sprang up to carry the torch.
--- [2]
I don't recall them refusing to support x86, but BSD development was mostly done by academics rewriting and improving AT&T UNIX, which was mostly on big iron systems of the time. They were focused on academic computer science work. The lawsuits stopped a lot of BSD work as the universities were sorting it all out. William and Lynne Jolitz start porting 4.3BSD to the Intel 80386 at Berkeley in 1989 (but the code wasn't released for years due to said lawsuit) before Linux existed. That is the first BSD-on-x86 work; by December 1990 they had contributed a working port to UCB. Most of the code didn't see the light of day until ~1992.
Also, usable and production ready BSDs were running large websites on x86 long before linux became mainstream and well-supported enough to be used. The BSD TCP/IP stack was the reference implementation for ages and BSD was heavily used in the internet's early days as a lot of early companies spun out of Californian universities. Hotmail ran on FreeBSD. Early SunOS variants were based off of BSD, as were some other commercial unixes.
The bigger killer, I think, is that BSD was (and still has) a bit of closed mindset to newcomers and were and are more conservative to new technology, despite some foundations of techbeing started with them. Docker's origins can be directly traced to FreeBSD jails. Sometimes the conservatism is warranted and a benefit (eg OpenSSH).
bawolff•Jul 12, 2026
I never believe people when they say, we would have been famous if not for one piece of bad luck 35 years ago.
Yeah, i'm sure the lawsuit was crappy and set things back. But if you can't recover after 35 years, then its something deeper than what happened 35 years ago.
oooyay•Jul 12, 2026
Even very smart, very accomplished people can be very wrong. Xen is seeing a resurgence from Xen Orchestra and I've used it in my homelab. It's quite pleasant. I also, of course, use de Raadt's software as well.
estebank•Jul 12, 2026
I think that everyone has the power to be wrong, but to be very wrong with convincing arguments, you must be smart.
A smart person can come up with post-hoc rationalizations that hold up under some scrutiny, to the point it is very hard to convince them otherwise. Add to that people who became famous or successful on the back of "being right" on some subject matter, getting used to "being right even in the face of overwhelming push back", and you have a recipe for very smart people being very wrong in very visible/loud ways.
tptacek•Jul 12, 2026
One of his dumber takes. Virtualization replaces an ultra-functional general-purpose kernel evolved over decades to support every conceivable application with a drastically smaller "kernel" (KVM and the userland hypervisor). It's a drastic attack surface reduction, and the empirical data bears that out: kernel LPEs aren't even newsworthy (there's whole repos full of unnamed, unremarked-upon LPEs), and KVM escapes are very rare.
ummonk•Jul 12, 2026
How big is the OpenBSD kernel and userland actually compared to a virtualization layer?
boricj•Jul 12, 2026
Doesn't that message date back to a time that either predates or is almost concurrent with the introduction of x86 hardware-assisted virtualization? I wasn't around playing with VMs back then, but I'm not sure that the track record of x86 virtualization 20 years ago was that great.
tptacek•Jul 12, 2026
It does, but that's an argument about implementations, and his comment is an argument about design. Just read it again and see if you think it's reasonable. Pay attention to the tone and (especially) the conclusory certainty he deploys.
SoftTalker•Jul 12, 2026
And since then, OpenBSD has developed its own VM subsystem vmm(4), vmd(8), vmctl(8).
tptacek•Jul 12, 2026
Sure, I mean, he was wrong, and I assume he knows he's wrong, and wouldn't say the same thing today. He's not dumb. Just this take is.
otterley•Jul 12, 2026
I’ll take someone who’s dumb over someone who is smart but rudely and confidently incorrect any day. Modesty, thoughtfulness, and kindness are too-undervalued virtues in our business.
tptacek•Jul 12, 2026
I agree with everybody else who's wondered why this got posted today.
otterley•Jul 12, 2026
I too wonder why as it’s not news.
That said, I don’t know whether Theo has since “eaten crow” or has otherwise personally evolved.
TZubiri•Jul 12, 2026
I'm anti virtualization, but mostly due to the internal complexities of the guest applications being swept under the rug, it's undeniable that the host is protected and thus neighbouring guests (of course it is with almost 20 years of hindsight I can say this.)
That the hypervisor is effectively an operating system/kernel I have always held, and that it is a smaller and thus less vulnerable kernel is an appropriate explication I think. It's very hard to secure an all purpose kernel like Linux without actually building it yourself (and even then..)
naturalmovement•Jul 12, 2026
If someone purposely dug up emails you wrote 19 years ago, I'm sure they'd find some of your "dumber takes" as well.
I'm not sure what the purpose of revisiting this is beyond provoking a flamewar on a slow Sunday.
tptacek•Jul 12, 2026
I mean, I agree there. We all have dumb takes! I hear roughly once a month about my old "I don't think Dual EC is a backdoor, it's too dumb and obvious for anyone to actually use it" take.
bawolff•Jul 12, 2026
Probably people are responding less to the dumbness of the take and more the arrogance of the tone combined with the dumbness of the take. Everyone has dumb takes, not everyone is an asshole while giving their dumb takes.
Regardless i do agree with you though, not sure what the point of digging up ancient skeletons is.
throw0101a•Jul 12, 2026
> If someone purposely dug up emails you wrote 19 years ago, I'm sure they'd find some of your "dumber takes" as well.
"Give me six lines written by the hand of the most honest man, I will find something in them which will hang him."
> replaces an ultra-functional general-purpose kernel evolved over decades to support every conceivable application with a drastically smaller "kernel"
Is a Proxmox kernel that much smaller than a typical Linux kernel?
tptacek•Jul 12, 2026
I don't know. I don't use Proxmox.
vlovich123•Jul 12, 2026
> A
simple tool was presented, iofuzz, that exposes exploitable
security flaws in most, if not all, virtual machines available
today. To the knowledge of the author, no similar research has
been conducted before. The results produced by crashme, a
tool well known for over a decade, locating trivial flaws dem-
onstrates this.
No virtual machine tested was robust enough to withstand
the testing procedure used, and multiple exploitable flaws
were presented that could allow an attacker restricted to a vir-
tualised environment to reliably escape onto the host system.
The results obtained demonstrate the need for further
research into virtualisation security and prove that virtualisa-
tion is no security panacea.
He’s not wrong based on the research at the time. The mistake is presenting this as if it’s something that will be true for all time. Is virtualization a panacea? No. CPU manufacturers can’t even protect against side channel attacks. But it’s completely missing what this provides which is that the difficulty and cost of creating an exploit is higher today than 20 years ago. And it’s amusing to hear someone blasting away at the security of others when BSD has its own share of problems and architectural weaknesses are discovered through popularity of your system being an attack target, not because you’re smarter than everyone else and made better choices (sometimes it can be true in places, but harder to maintain for a big piece of software like an OS)
DonHopkins•Jul 12, 2026
My favorite Theologism:
"My favorite part of the "many eyes" argument is how few bugs
were found by the two eyes of Eric (the originator of the
statement). All the many eyes are apparently attached to a
lot of hands that type lots of words about many eyes, and
never actually audit code." -Theo de Raadt
I think de Raadt and OpenBSD are hugely overrated and some takes are as dumb as the one in the post.
OpenBSD is only secure because because it does pretty much nothing and does it very slowly (its firewall just recently broke the 4gbps firewalling capabilty, for example) but somehow a cult has formed around it ¯\_(ツ)_/¯
bawolff•Jul 12, 2026
In fairness, minimizing surface area (doing nothing unless you need to) is security 101, so i hardly think that is a criticism.
hylaride•Jul 12, 2026
Counter-take:
Linux is only secure because of OpenSSH.
In all seriousness, the OpenBSD guys are very conservative with technology. The OpenBSD pf stack (as well as much of the kernel) isn't heavily threaded due to the risk of race conditions. They also (correctly) predicted a lot of the speculative CPU attacks by not supporting it by default.
They've done a lot of security research and pioneered a lot of open source work around OS-level stack smashing technologies, like memory executable-space protection (W^X), early process privilege separation, memory space randomization, etc. Some of these features are not great for performance, but do help and have been adopted by other systems.
You're basically arguing that an armoured car sucks because a Ferrari can smoke it on a race track. There are times you want a Ferrari and there are times you want a Brinks truck.
rustcleaner•Jul 12, 2026
If OpenBSD pretended Qubes OS was a feature prototype/reference OS build and made a fork of OpenBSD to feature-match Qubes OS (calling it QuBSD or something), that would be great!
jurgenaut23•Jul 12, 2026
god bless usenet. The good ol' flame wars aren't what they are used to anymore with all this moderation and trolling feeding each other around here.
brynet•Jul 12, 2026
This is not usenet, it's the openbsd misc@ mailing list.
1vuio0pswjnm7•Jul 12, 2026
It appears this mail thread from 2007 was about Xen. NetBSD was an early adopter, not for security but for experimentation
Meanwhile Amazon was using Xen for AWS
Later a "security researcher" used Xen to create the "Qubes" OS
10 Comments
https://www.reddit.com/r/emacs/comments/1tf1iy/imap_inventor...
>From: Mark Crispin, To: comp.lang.emacs
>What mindless cretin thought that it should be a good idea to make line-move-visual be the default in emacs 23? I just found out about this charming "improvement" in the worst possible way. Investigation determined that a "routine" software update had just installed emacs 23 and gave me this "improvement".
>People wonder why everybody hasn't dumped proprietary desktop software. This is an example why. Emacs' line behavior has well over 30 years of history, and some bagbiter goes and changes it BY DEFAULT.
>Add all the cute new features you want. But leave the goddamn defaults alone.
>If you want to have your own playpen where you twiddle defaults to your hearts content, have at it. But don't pretend that you produce software for a production environment, and stop telling the Linux distributions that they should "upgrade" to your "improved" versions. People doing real work depend upon those distributions.
>It does no good to say "read the release notes" when the affected users don't get the release notes and don't even know that a new release happened. It is also unreasonable to expect users to subscribe to every obscure newsgroup, forum, and wiki to hear about changes that will turn their expectations upside down.
>Yes, I fixed my .emacs file. And I'm putting in the same change to all the .emacs files on all the dozens of other machines I use, even though they still have emacs 22, because otherwise this unpleasant surprise will repeat itself over and over again.
>Grr.
>From: Mark Crispin, To: comp.lang.emacs
>They made the wrong decision. Changes to default behavior are a bad idea. Changes to default behavior of the most basic functionality are an extremely bad idea.
>I don't care if M-X fart-noisily-with-spray changes its default scent from skunk to lemon. But I damn well do care about the most basic operations: all CTRL single letter and ESC single letter. After 33+ years of using emacs, I expect these to be reliable and not suddenly change.
>I wasted hours trying to figure out what the hell was wrong with my file, or my terminal emulator window, or my system. The fact that the problem went away on a different system added further confusion. It was only when I did ESC <n> CTRL/N and saw that it moved me the wrong number of lines, but only on one system, that I realized that emacs changed. And that's when I did ESC X describe-key CTRL/N and read about line-mode-visual, although it did not mention that this was now the default.
>Surprise. Grr.
ESR's free to make ridiculous laws that aren't true, but blaming it on Linus was a dick mode.
https://github.com/porridgewithraisins/x11cp/blob/main/rant
https://www.forbes.com/2005/06/16/linux-bsd-unix-cz_dl_0616t...
Imagine being so hard you're labelled as "difficult" by no other but Linus Torvalds
"De Raadt says BSD could have become the world's most popular open source operating system, except that a lawsuit over BSD scared away developers, who went off to work on Linux and stayed there even after BSD was deemed legal."
There is some truth to that. And who knows where BSDs might have been if the lawsuit never happened.
However, I think Linux has always has and till today has better leadership, and management compared to OpenBSD.
I also think GPLv2 was another good that happened to Linux. It just creates an irresistible force to contribute back. With *BSD, a company might contribute back or it may not.
And I guess I do think that FreeBSD had a saner organization pattern than the sort of haphazard ecosystem of projects that grew up around GNU and Linux. Maybe the chaos was necessary for growth, but it still seems to be a hurdle for new Linux users in the current day.
it's dead as of july 2023: https://www.debian.org/ports/kfreebsd-gnu/ :
> The development of Debian GNU/kFreeBSD has officially terminated as of July 2023 due to the lack of interest and volunteers. You may find the official announcement here[1]
here[1]: https://lists.debian.org/debian-devel/2023/07/msg00176.html
oh boy its' much worse than that: KDE/GNOME were already largely precarious before that.
The whole Xorg thing was really dependant on gpu drivers and the story between linux gpu drivers and *bsd gpu drivers was so much different. Having the BSDs be fairly different didn't really help (eg: only FreeBSD had official nvidia drivers, albeit proprietary).
Gnome did take a lot of backlash and Gnome essentially became a meme at some point ("what's the use case for that?")
Gnome did take a strong dependency on systemd (both gnome and systemd are developed by Red Hat, btw).
And Gnome also did push a lot for wayland (that wasn't implemented on the various BSDs for a long time).
I haven't checked in a while, but I think Gnome is wayland-only nowadays ?
Ultimately, the real issue with KDE/GNOME and the BSDs is that the BSDs are largely irrelevant and essentially only relevant for some specific use-cases where desktop usage is not involved.
The lawsuit didn’t help. But the BSD developers shot themselves in the foot when they refused to support x86, referring to it as a “toy”.
It wasn't until Linux came along and started eating up all of BSD's user base that they freaked out and decided x86 support might be a good idea. But by then it was too late.
Generally speaking the BSDs seems really fork-a-phobic and it kinda shows given how little dynamism is there in the development those systems.
Even the Solaris derivatives have a faster tempo.
When was that? Presumably wwaaaaaaaay before 386BSD was a thing right?
Quotes below:
[1] https://www.doc-reform.org/spine/en/html/free_for_all.peter_...[2] https://www.sisudoc.org/spine/en/html/free_for_all.peter_way...
Also, usable and production ready BSDs were running large websites on x86 long before linux became mainstream and well-supported enough to be used. The BSD TCP/IP stack was the reference implementation for ages and BSD was heavily used in the internet's early days as a lot of early companies spun out of Californian universities. Hotmail ran on FreeBSD. Early SunOS variants were based off of BSD, as were some other commercial unixes.
The bigger killer, I think, is that BSD was (and still has) a bit of closed mindset to newcomers and were and are more conservative to new technology, despite some foundations of techbeing started with them. Docker's origins can be directly traced to FreeBSD jails. Sometimes the conservatism is warranted and a benefit (eg OpenSSH).
Yeah, i'm sure the lawsuit was crappy and set things back. But if you can't recover after 35 years, then its something deeper than what happened 35 years ago.
A smart person can come up with post-hoc rationalizations that hold up under some scrutiny, to the point it is very hard to convince them otherwise. Add to that people who became famous or successful on the back of "being right" on some subject matter, getting used to "being right even in the face of overwhelming push back", and you have a recipe for very smart people being very wrong in very visible/loud ways.
That said, I don’t know whether Theo has since “eaten crow” or has otherwise personally evolved.
That the hypervisor is effectively an operating system/kernel I have always held, and that it is a smaller and thus less vulnerable kernel is an appropriate explication I think. It's very hard to secure an all purpose kernel like Linux without actually building it yourself (and even then..)
I'm not sure what the purpose of revisiting this is beyond provoking a flamewar on a slow Sunday.
Regardless i do agree with you though, not sure what the point of digging up ancient skeletons is.
"Give me six lines written by the hand of the most honest man, I will find something in them which will hang him."
* https://en.wikipedia.org/wiki/Give_me_the_man_and_I_will_giv...
Is a Proxmox kernel that much smaller than a typical Linux kernel?
https://taviso.decsystem.org/virtsec.pdf
He’s not wrong based on the research at the time. The mistake is presenting this as if it’s something that will be true for all time. Is virtualization a panacea? No. CPU manufacturers can’t even protect against side channel attacks. But it’s completely missing what this provides which is that the difficulty and cost of creating an exploit is higher today than 20 years ago. And it’s amusing to hear someone blasting away at the security of others when BSD has its own share of problems and architectural weaknesses are discovered through popularity of your system being an attack target, not because you’re smarter than everyone else and made better choices (sometimes it can be true in places, but harder to maintain for a big piece of software like an OS)
OpenBSD is only secure because because it does pretty much nothing and does it very slowly (its firewall just recently broke the 4gbps firewalling capabilty, for example) but somehow a cult has formed around it ¯\_(ツ)_/¯
Linux is only secure because of OpenSSH.
In all seriousness, the OpenBSD guys are very conservative with technology. The OpenBSD pf stack (as well as much of the kernel) isn't heavily threaded due to the risk of race conditions. They also (correctly) predicted a lot of the speculative CPU attacks by not supporting it by default.
They've done a lot of security research and pioneered a lot of open source work around OS-level stack smashing technologies, like memory executable-space protection (W^X), early process privilege separation, memory space randomization, etc. Some of these features are not great for performance, but do help and have been adopted by other systems.
You're basically arguing that an armoured car sucks because a Ferrari can smoke it on a race track. There are times you want a Ferrari and there are times you want a Brinks truck.
Meanwhile Amazon was using Xen for AWS
Later a "security researcher" used Xen to create the "Qubes" OS