I've been on HN since 2012-ish, but a reader since way before. In the last 5 years alone, HN has unfortunately become extremely political, steering most conversations in the direction of political correctness rather than technical objectivity. I don't think it's a problem of moderation, because, that is still quite good. I think it's just the evolution of forums in general. Invariably, someone will start with FUD or ragebait and every discussion that follows will be trying to address that instead of the technicality behind the topic. Partly, we are also to blame - a lot of the top stories on HN these days have nothing to do with technology to be honest. You'll find the most random stuff on the HN sometimes - "Why geese mate for life" or something similar that makes you wonder "what the fuck am I supposed to do with that information now?"
the evolution of english speaking forums*. Which is rather unfortunate as a tech entusiast, as Russian forums are dying down and the only alternative are the walled Chinese forums.
we could create a new HN in 10 minutes, one that expressely prohibits politics AND posts about how many eggs chickens lay in a week (where half the comments would probably end up discussing the decision in 2020 of the american gov to cull infected chickens), but it would have approxitely 0 users.