What R16 said about gay people becoming hyper-observant as a result of being outsiders articulates something I've long thought. Also agree with the poster who pointed out that use of books as an escape also had the side effect of educatiing us about grammar and "high" English usage, which can curdle into pedantry.
I've also observed (along with other posters), eldergay snark aside, that those of us past our mid forties grew up in a much less accepting world--we didn't get the real high school dating experience and either entered bearding relationships (and got divorced) or tried to forge relationships in a society which actively tried to bust us up. As a result, few if any of us escaped emotional damage and more of us are alone in mid or later life. The poster who said it's lack if sex isnt wrong, but that's incomplete--we are less likely to experience smoothing of sharp edges that comes from the day to day intimacy with another person. Wives and children don't have the same effect on a gay man. So you have a a lot of guys who are emotionally very inexperienced with their endless lists of relationship dealbreakers that no human being on earth can fit.
It's also part of a greater social trend brought on by The anonymity of the internet and the way immersion in the online atmosphere of discourse creates these ideological echo chambers where you're detached and behave in an untempered way you never would in the real world. This has nothing to do with Trump, this was well established long before he ever ran for President, but this mindset has spilled into the real world and is starting to characterize political journalism and media, scaring off any candidates and journalists who don't thrive in the crude, unnuanced new world.
It's been a trend for the past 50 years, really--an unfortunate byproduct of the counterculture of questioning authority and the normalizing of nonmainstream social groups is the normalization of a lot of antisocial behavior as the price of living in a pluralistic society. People are less inclined to censor themselves, even when they desperately need to.
So,it's not that gays need to chill more, OP,it's that society as a whole needs to UN-chill a bit, pull themselves together and remember theyre not silent or invisible. Besides which, as R37 pointed out, "chill" people are often every bit as judgemental and superior as their straw man counterpart of the tsking old queen with his ascot and little dog, they just mask it with passive aggressive it's-all-good-ness. You're just seeing it in gay people because you're on a gay site. I assure you, there are plenty of histrionic straight drama queens.
Which brings me to what R32 pointed out--a lot of what you're reading on the DL is a performance of sorts, written specifically with a comedy audience in mind. We're venting and trying to do it entertainingly. So though i might silently scream inside every time I see someone begin a sentence with "Um..." which might also include the phrase "you do know" and conclude with "don't you?" I'm not only not going to refrain from shooting them but I'll still be friends with them. I'll just come here and bitch to the DLosphere about it.