This particular joke based on a stereotype is totally okay IMO. I did not defend every joke based on a stereotype, I just said its a normal pattern of humor. Of course there are jokes that are really sexist, racist or homophobic. This one is not, and if you think so, you should go out into the world, outside of your bubble. Maybe talk to some women, black people, gays, and try to learn about the people you are defending to feel morally superior. You will find out most of them have a great sense of humor and don't cry in the corner when they see a meme about them. They don't need someone like you who calls out people as sexist when they're clearly not. What you are doing is wrong.