Any troll or shitposter who can't operate extremely effectively on HN isn't very good at it.

The site basically has a house style for those activities, and you can go crazy insulting and stirring people up all day long and not get moderated for it, as long as you stick to the approved style. Bonus: if you're not just half-competent, but actually good, you can probably get people calling you out on your behavior moderated, if they don't beat around the bush about it in just the right ways! That's why the majority of posts on here are trolling and shitposting, or fallout thereof.

If you stay under the moderation radar, trolling this place is like shooting fish in a barrel, even easier than most sites (no, I've not done it, but it's very obviously most of what goes on here). If the site cared about this, it'd have ignore-lists.

Right that's why everyone here still acts like redditors that don't read headlines, downvote without explanation, have massively long threads arguing without listening to each other, spam for self promotion...