Theranos and its ilk were all no surprise to me. The entire venture ecosystem is perfectly designed to catch charlatans, not experts.
On the other hand, I think it's common to see threads that have a high ratio of signal to noise. Like a link to a scientific paper will have one of the authors of the paper in the comments section answering questions.
So it is ironic and kind of funny when you realize that, apart from a few outliers, Hacker News is just as infested with trolls, fools, posers and Dunning-Krueger as the rest of the web.
It is just a more polite /g/ without the pictures and memes. That's not an insult, just an observation of how deeply the sets of users here, there, on Reddit and elsewhere overlap.
No, it merely hides the insults behind 300 words of passive-aggressiveness.
If only, at the least, because the guidelines for HN discourage pointless and inane commentary. Reddit is very likely 95% funny one liners on the most active threads.
There are observably obvious differences, even if you don't agree with any inferences made from them.
Also, Reddit is not 95% funny one liners in technical or programming forums, and the guidelines for those often also discourage pointless and inane commentary. Go look at /r/askhistorians for one example. Reddit does have a higher tolerance for humor and memes than HN, but humorlessness is not necessarily an indicator of quality.
To your first point, I also concede that this phenomenon certainly does happen, but would counter with the notion that this probably happens with every conversation ever, with it perhaps tapering off in materials science discussions amongst experts.
I'd assert that it's happening right now, given that neither of us are likely informed enough to empirically support our assertions here. We're merely sharing our rather vague impressions.
That's fair. A lot of what happens here can probably be described as anecdotes sparring with other anecdotes.
If you make peace with this you will be much happier.