Thanks for finding that, I had a brief search but couldn't locate it.
Yeah, most communities have bad actors, but in HN's case, most of the bad comments are either user-flagged or killed directly by dang. The crazy part is that some of these people (e.g. sussmannbaka in the thread you linked) actually think that that means that those comments are somehow endorsed or something, which is completely insane - the comment literally says "dead" or "flagged", that means the community doesn't think it's acceptable.
The behavior in both the Mastodon post and that thread is why I don't want these people on HN - they're not interested in intellectual curiosity, they just want to have a flamewar over nothing.
Do you have any recent examples? This has never been my experience, and in the post I linked, other users fail to find such examples too. It also seems strange to me to complain about comments/posts that are moderated?