I don’t watch, or read, comedy for precisely that reason. Comedians and comedy writers seem to have the impression that profanity, vulgarity, and stupidity, are funny. As Laura said, instead of jokes or good comebacks, it’s easier to throw in the swearing, or rely on crudeness. At least, that’s what seems to make it into the final product, from the admittedly small snippets I’ve been subjected to in advertising and by accident.
IMO, animals and small children are far funnier than adults acting stupid, making fun of others, or displaying their repertoire of nastiness.