The only hardline view on security you'll encounter in the wild is "security is practical in our computational environments"[1]. Only half-joking here.
My reading of Theo's quote is merely "the combination of x86/IA32/AMD64 and virtualization gives little to no factual security benefits, and plenty of pitfals".
I don't see Theo as being a hardliner about security, just meticulous about good engineering practices - as per OpenBSD's usual standards - and facing the problems & risks as they are.
[1] examples: "Rust/Java gives you security", "shortlisting the only allowed actions by end-user application gives you security", "hardcore firewalls give you security", "virtualization gives you security", "advanced architectures like Burroughs' give you security".
The new class of attacks we now see target any type of shared code execution environment. OpenBSD is as vulnerable to this as anything else.
Reminds me a friend who worked on Javascript in the early days said it was the only thing that had any hope of providing minimal security at the time. Because Windows 3.1 and 95 +0x86 was a security trashfire.
"""> Virtualization seems to have a lot of security benefits.
You've been smoking something really mind altering, and I think you should share it.
x86 virtualization is about basically placing another nearly full kernel, full of new bugs, on top of a nasty x86 architecture which barely has correct page protection. Then running your operating system on the other side of this brand new pile of shit.
You are absolutely deluded, if not stupid, if you think that a worldwide collection of software engineers who can't write operating systems or applications without security holes, can then turn around and suddenly write virtualization layers without security holes.
You've seen something on the shelf, and it has all sorts of pretty colours, and you've bought it.
That's all x86 virtualization is. """
[1] https://marc.info/?l=openbsd-misc&m=119318909016582