I think you're confusing "jokes about Nazis" for "Nazi-type jokes". A Nazi isn't very likely to joke about the semblances between fascism and some far-left identity ideology for the same reasons far-left identitarians don't make those jokes. And my "You know who else drank water? Hitler!" example is a common example of a satirical joke about Nazis, so clearly ordinary people do tell jokes about Nazis (to varying degrees of subtlety).