Banning politics is a political stance. It means that the only allowed politics are the status quo. It also means in message boards that the mod's political beliefs are what is allowed.
Asking why is a waste of time in an online space with such rules.
Most memes have nothing to do with the person in the meme. I doubt crowder himself made the meme, even if he did it doesn't really matter as the meme has transcended the person st this point.