I don't know, I don't even feel like it's just this board. I feel like external society is changing pretty quickly, too. Things are getting much harder than they were.
I don't know if this is what you're referring to, but I feel like tensions are just rising in general. I've been feeling that for a very long time, but I think it's starting to get really tangible. People are drawing stricter lines between each other and getting more derisive about those who don't fall on their own side. There's a plethora of issues I could have brought up 5 years ago and almost anyone would shrug at them, but now almost anyone has very strong opinions on.
I've gotten a similar sense, and it's not something limited to this board. I think economic stress, a culture of cynicism, a growing air of disillusionment with the system, and no clearly-visible way forward, have been driving people toward tension and unrest. These factors might not affect everyone, but they bleed across from the people we meet and interact with who are dealing with these things, until that air becomes pervasive, and people get more stressed and snippy with one another.
It's interesting to me, to look at common themes in modern media as a way to suss out what's on people's minds, and what fantasies are appealing to them right now... sort of a window into the Zeitgeist. These days, most new shows and films seem to be about individuals rebelling against a corrupt society or dystopian government, or about bands of oppressed and isolated individuals uniting in rebellion against zombies, alien invaders, or other stand-ins for a world turned against them. I don't watch much television, but what I know of The Walking Dead, The Hunger Games, Falling Skies, Game of Thrones, Revolution, even Breaking Bad and Dexter, indicates that they share in these themes.
A lot of people are working harder, earning less, and are generally less happy about the system/world they inhabit than they were a few decades ago. I suspect that's why a lot of people are fantasizing about rebelling against it, or tearing it all down to rebuild it anew. As technology opens the world up, a lot of people are getting more and more insular, and gravitating into specialized communities like this one, where they seek out people with similar ideologies... perhaps to reassure them in their normalcy. And as we divide ourselves into more and more specialized groups, that divisiveness could very well be driving us further apart.
PPE: I don't know how accurate this all is, as I'm mostly just stream-of-consciousness rambling at this point.
Angst! Ennui! Bleh! etc.