My best guess is it starts from a place of empathy.
If you were a dude being shoved in a locker in the 80s because you liked D&D, you might start to be more tolerant to the gay guy having the same attitude shown towards them. You're all societal rejects who will never be accepted for who you are. But fast forward 30 years when the minorities and you aren't being bullied/ostracized nearly as much but you still think you are. You and all the social misanthropes have either got a job in game design, film, music, IT, teaching, ect.
You still think every conservative is Biff Thundercock, who either bullied you at a time where it was more socially acceptable to do so or just had a social grace that you never could attain, or every christian are your parents who kicked you out of the house for playing an RPG or listening to Black Sabbath. You don't want to be in any way like the people who made life hell for you decades ago, so instead of adapting any nuance or understanding how the world has progressed, you still put everyone who in any way reminds you of the people who rejected you when you were young in the same bubble and insist that they can't like what you like or be in a similar boat you were once in. Because how could the guy who likes anime but also wants to exercise and/or doesn't hang around protected classes be like you?
So you reject these people who for all intents and purposes have the same opinions you had when you were younger and double down on embracing LGBTQ rights, veganism and your hatred for religion because you view those as the "outsider" culture, even if they have become the literal opposite and are now the mainstream. You blackball people from your artistic industries, consider any harassment they may get as completely justifiable and say they shouldn't read/listen to/watch your stuff. You then are surprised when people don't like this and hold you accountable.
Now you have people who are essentially the modern day jocks who would've beat you half to death celebrating you, adopting your lingo, culture and style without any of the pushback that you would have had. You then are also surprised when these total social misfits want to drop you when your past comes to light that reveals that you did the kind of questionable sexual activity that usually comes from someone who has very little experience properly interacting with women, which for a large section of your life was you. You then deal with the same social pariah status you did before but still internalize it and forget the world is for all intents just the same as it was when you were in highschool, just with a new coat of paint now.
Nevertheless, you're happy that you and all the freaks and geeks are still doing your due dilligence to fight back against the jocks and "toxic masculinity" or "white privilege" or "fascism" that you experienced as an adolescent and never bothered to reform your thoughts about into adulthood. Meanwhile all of the people you have formed the entire crux of your entire life philosophy around are either dead, don't give a shit about you, or found jesus and would probably apologize to you if you met them again. And your fellow "nerds" are now the schoolyard bully or cliquey mean girls and you're none the wiser.
TL;DR Don't let the fact your parents made you go to Church on Sundays or you were called a faggot a couple of times in the locker room haunt you into adulthood so much that you end up almost irrevocably destroying every facet of your country in your lifetime.
