I think the problem is when people try to cram their politics into everything and everywhere and they look at everything through that lens when really it isn't very related (see the sjw infiltration of every formerly fun sub on reddit). I don't see a problem with posting something if it's related but I'm not gonna be upvoting some mess about "here's a fat person they're probably a libtard lol" or whatever. So far the community does an ok enough job without official rules outright banning politics, and I think posts like this are part of the self-policing that keeps things running well and reminding people to try to stay on point.