This happened to me. I think on some intellectual level I understood that work friendship wasn't terribly authentic and based on the politics of getting ahead. Then I was on the receiving end of some very dishonest politics and it really opened my eyes on how terrible some/many of the people here are and people I've had unbelievably good relationships with will turn on you in a very aggressive manner instantly if they think picking the other side will gain them more benefits. Fairness, truth, etc didn't matter to them. Holy cow, I just couldn't believe it.
Ironically, this has made me appreciate the people who are openly jerky at work. At least they're open with the biases. There's probably something to be said about white collar workplace culture's default of "aren't we all just friends and teammates?" It seems to empower only the worst political players. At this point, I'd probably rather work with a bunch of jerks who are open with their biases than a bunch of 'office friendly' people who are only friendly because it serves them. There's a certain level of honesty with the jerks.
I also see this in myself. I've learned how to play up false modesty and the whole "Aren't we just pals" attitude, and I don't like it now that I'm self-aware of it. I don't know if I'm ready to become an full-on office jerk, but I'm probably half-way there now and life seems a lot easier when you're more open with your biases and honestly accept that most of your coworkers are adversaries, not teammates. I'm sure I'm more disliked, but disliked by people who would just turn on me anyway if push came to shove. I also invest much less mental energy into trying to be everyone's buddy and instead focus that on the work itself, anti-burn out strategies, leisure time, my creative projects, planning my next career move, etc.
I used to laugh at the grumpy gray-beards in IT. Now I see where they are coming from. The sooner the automation/robot revolution comes the better. Work is a zero-sum game that best serves the extremely dishonest. I don't know why we're so worried about moving into a post-work and post-scarcity society. The status quo is pretty terrible if we're being honest about it.