Because noobs don't realize they can subscribe to other streams so they can only post in fun, gaming, sports and politics. They run out of subs and post their non political crap here.
This site use to have all memes on one stream. Then the left got triggered seeing pro trump memes get on the hotpage, so they complained until imgflip split the streams. That's why I think this should be strictly politics. Pro trump memes don't get featured in fun. Anti ones do tho.