I certainly wouldn't argue with that point but I think if you ignore your made up examples and actually look elsewhere in the thread you'll agree as well that the criticism above was not misplaced.

I'm not saying the comments on this post are rigorous. I'm saying the ones elsewhere on HN are not. I therefore see rather less of a disparity between these comments and "the average HN user" than the commenter at the top of this thread. It's just more obvious to them because they don't agree with what's being said.

(Edit: That said, my example 2 seems pretty relevant to at least some of the comments here, no? Eg. https://news.ycombinator.com/item?id=45048410. And my example 1 isn't at all made up: it's a claim made very frequently on HN, and usually implied to be self-evident.)