Comedy works by being transgressive against hemlines.
Looks like it's working.
My problem with Gillis is his aw shucks thing wears thin, quickly. He's average. But, the very best comedians leave everyone in the room uncomfortable and irate. Otherwise it's just a mean girls session with your funny friend, and that's lame.
I love Rivers and Carlin, but they were always "Hey, those people you hate? I hate them too; I'll make jokes at their expense!" Fan service. Pryor, Chappelle, and Louis have said things that have made me feel angry and personally attacked, and have made me wince and react they're awful for saying something like that. That's why they are exceptional.