[fractionalhare]

You will also see entire threads of people confidently stating utter speculation as if it's fact. HN is well-moderated and has high information density compared to most subreddits, but that doesn't mean the information is correct. What you see on HN is that both correct and incorrect comments tend to adopt the same academic affect in their writing. If you're not fairly familiar with the subject at hand, it's hard to tell who knows what they're talking about because it all sounds coherent and reasonable.

If you really want a lark, read the typical HN subthread on a topic involving trading, finance or economics. It's like watching the YouTube-educated spar with the Wikipedia-educated. Commenters with real world experience are downvoted just as often as they're upvoted when they try to earnestly correct mundane misconceptions.

Likewise you can't have a bug bounty story on HN without someone repeating the farce that web app vulns have some sort of shadowy black market. There is invariably a comment near the top claiming the security researcher could have received so much more money by selling it to criminals. It is amazing that something so wrong gets repeatedly so carelessly and easily.

These are a substantial number of people here who think they can confidently talk about anything if they just deconstruct it to first principles and treat it like something else they know about.

[autocorr]

I think this is the main thing, which is that the quality of the discussion really depends on the topic. As a post-doc in astronomy, I'm happy to report that the quality of HN discussion on astro-related submissions tends to be quite good[1]. The top level posts tend to be either be broad-level questions that get some good replies or "fun facts". This probably has to do with most folks being interested in space but not really having strong opinions, leading to cordial comment sections and a decent supply of actual astronomy experts on HN.

Now, for things like finance, markets, politics, etc. like you're getting at, those are a different store. I've been baffled that some political and finance posts have devolved to threads worse than Reddit... Maybe some subs have become homogeneous enough that they don't generate quite the same conflict?

[1] About once a year there's a Dark Matter related post that usually brings out a very critical set of responses. That and Dark Energy are just things you need a lot of investigation into the evidence of because, like Quantum Mechanics, they are just weird and don't make sense to the uninitiated.