Don't think it's the same group of people, it feels like intelligent and mentally healthy individuals have been opting to abstain from online discussions in general over the last few years in droves after realizing their time and energy and better spent elsewhere. Especially with the trend of comments being taken out of context to attack individuals employers/livelihood. That leaves the young, socially broken and depressed (myself included).
So that said; where do people go online who want to have serious (tech) discussions? Must be some secret place with a person like Linus kicking everyone out he doesn't like at first offense.
Apart from that, technical forums for specific topics, like the ones for certain Linux distributions or other open source projects, have their merits; but they are naturally limited in the breadth of topics discussed. (Some might have very interesting and broad off-topic discussions though)
I've also had a couple of brushes recently where what I considered reasonably calm and uncontroversial posts on a technical subject got alternating up and down votes for hours. I don't recall that happening before.
Maybe that's just a sign of my growing older, but I think some of it might be the degradation of the community's general moral.
Articulating myself, to myself, even if I don't share it, is often worthwhile. Why do I agree? Disagree? Is my observation novel? Enough to share?
Once I figure out what I'm thinking, do I care enough to share? Is the recipient worth my time? Do I really want to interrupt someone who's digging themselves into a hole?
Etc.
When I first started browsing hn I was blown away with how smart and insightful the posts were. Ideas I had never thought of and quite a few I struggled to even comprehend.
It's very rare to see that now days.
I was the hub of a PC-Relay network (the FidoNet era), a moderator on CompuServe, and very active on various game boards. It's never been any different.
Social circles have a life cycle, span.
When the current one sours, go find the next one. Or start a new one with some friends.
I think Clay Shirky's article about a group being its own worst enemy applies. Probably monkeyspheres too.
Intelligence isn't a ladder, so that wouldn't make sense in any context. Effective understanding of the relationship of Google vs God vs a domestic country's population vs yourself, does require some sophistication that involves general intelligence (in aggregate) and education. There are correlations with median income and these factors. As the population of the world gains access, simplistic fears about shadowy organizations are bound to gain ground from a myriad of historical and cultural parallels, as the median education level falls (among other associated factors, like wealth).
But also the stubborn, the foolhardy, and the idealistic.