The signal to noise on HN is something like 1:100.
It's sad. I don't comment here anymore simply because there is no point when you never get comments from people who even bothered to read what you wrote or will honestly disagree.
Worse there are people who go out on personal vendettas, engage in nothing more than harassment and a form of stalking, and those people are not punished, but dare to post scientific information that disagrees with global warming and you get hellbanned.
That's the cause- the moderation is done by unaccountable people who moderate for political correctness at least as much for politeness. Certainly people who cant' muster anything more than personal attacks are allowed to get away with it, while those being attacked are often censored.
The people who are the cause of the problem like the situation because their egos are getting stroked, so they see no need to change it.
I've solved it for myself-- I just never bother to read the comments these days (for many months at a time.)
If there's nothing intelligent said on hacker news comments, why bother with them?