Your anecdote does not make GP's comment "patently untrue". It's just a counter-example, and we don't know how prevalent your scenario is compared to GP's.
(And I agree with the GP. I'm fairly cynical about most developers' security stance and threat model. Source: my own usage patterns.)
Why should they apologize? All they did was point out that you just provided a counter example, not statistics (thus "we don't know how prevalently your scenario is" yet), and share a personal opinion.
You should also clarify that you pulled your statements out of your butt to look edgy. Everyone in every team I worked for the last ten years use docker. Docker is old tech. If you and your cavemen devs ignore what it is, that's your problem.
Sure, modern containerization is objectively good and should be used pretty much everywhere unless you have a strong reason not to, but the unfortunate reality is that it is nowhere near as universal as it should be.
Docker is old tech, yes, doesn't mean every dev in the world uses it. They don't. Jails/zones are even older (hell a chroot). Did developers all use those before due to them being 'old tech'. No.
Any reasonably big project uses docker because it's a very simple way to have the exact environment in both production and in dev. Also it is helpful for keeping things isolated. In all projects I've worked for the las ten years for several major companies, docker has been a requirement.
I'm aware of what docker is, I've been using it myself since it's inception and the tech I listed even before that. I'd recommend not assuming everything you have seen applies everywhere, to everyone else.
In my experience more than 9/10 programmers I've worked with have never used Docker before and of those who have, the majority have never used Docker for anything personal.
If I hand them an image for a Dev Container, sure, they might use it, but it becomes "a thing we need to do, to compile our code in our IDE" not a tool they would use for isolation*.
*) OP seemed to imply that containerization would be nice for safety and security compared to bare metal, but containers were never built for isolation in the first place, mind you. They are namespaces and chicken-coop-like-jails at best.
I don't use them in the way the heavy docker users use them but I have been using docker and even earlier Linux on Linux container solutions for decades.
There was some user chroot thing early on that required me to make a library to intercept the setuid calls to pretend the garbage root-only build system was running as root on everyone else's lowly user account.
And that's not even including the myriad of distroboxes I need to do anything at all on my gaming pc.