Let's suppose you're black and go over to a white friend's house for movie night. He puts on something super racist (say, Birth of a Nation, or a collection of blackface routines). You object, but all of his guests mock you for being "too sensitive" and "too political". You say, "I'm not sitting here for this," and leave. Were they rightfully unhappy with you?
I would say no, that your friends are assholes. That you aren't obliged to silently endorse your own oppression.
And I think it's the same thing at work. Would I want endless off-topic discussion at work? No. But some of what people denigrate as "too political" is entirely material to the workplace. Indeed, the Basecamp mess shows clearly that "no politics" rules are about suppressing discussion of things that are relevant, and are necessary because they are relevant.
most people don’t go to work to recreate, so this is a bad example.