It wasn't specifically you, but IMO your comment is guilty of the charge I was making:
What I see when reading this is a system (...) that is very poorly designed.
I know it's just your opinion, so what? Everything that people write on here is their opinion. But in true Hacker News style, you're straight out declaring that the low level internals of Linux memory management are rubbish. Not just poorly designed, but very poorly designed. As you say yourself, 'to suggest the author is an idiot'
Before this declaration, did you pause and think that maybe, just maybe, the kernel code authors might not be idiots? Or perhaps, you might have reflected, the kernel developers may have considered various different memory management schemes, maybe they weighed up the pros and cons of different approaches and found the current system to be good? Did you entertain the possibility that there might well be other non-obvious considerations that influence the choice of data structure? Apparently not, because you're happy to quickly declare that it's terrible code.
I'm not declaring you to be an idiot. It's the fact that you and others on here launch straight into the full-on 'this is/they are stupid, they should obviously do this' kind of statements, showing a dearth of empathy and a complete failure to look at the other side's view.
I'm not trying to shut down discussion. I'm not saying the kernel is perfect, or that the developers are beyond reproach. I'm not saying ignore years of work. It's the way in which some HN users, like you, jump into extremes of viewpoints (even your response is full of it too, with the questioning about perfect, cannot discuss problems, etc)
And the rust comment was a throwaway joke, HN commentators cannot seem to resist putting a 'do it in rust' comment somewhere in all code discussion...