It's some sort of Gell-Mann-Amnesia-like effect. I am accustomed to seeing thoughtful, informed discussion about technical topics on HN, so then it's jarring when something like this hits the front page and nobody seems to have any idea what they're talking about.

It's opposite Gell-Mann-Amnesia: I am a SWE and I come here because I find it one of the best places to keep abreast of the broader software world, not just the little corner of it that I'm currently working in. So in the things that I know well, I trust it. My wife is a medical professional, and so I know just enough to see that most medical conversations here are complete and utter nonsense.

So the mental model I have of the average HN contributor is basically that they are all SWE's- they know software engineering extremely well, and the farther you get from that the less valuable the conversation will be, and the more likely it will be someone trying to reason from first principles for 30 seconds about something that intelligent hard working people devote their careers to.