That's the biggest thing imo. Twitter is filled right now with this idea that it was probably an ultra conservative person ruffling people's feather and they were tired of the arguments between transphobic and lgbtq people or something.
I don't work at Basecamp, but I find that unlikely: they'd likely have fired the transphobic person (or at least I hope they would have). They didn't say they wouldn't do politics, just that they didn't want politics discussed over company infrastructure.
But even if the room was all on the same side of the political pendulum, things still get pretty ugly.