I did not think it was that bad.
Kramer was trying to improvise something entertaining and he failed.
He was also trying to reprise being a nut, but even failed at that.
Well, it was. You are free to think it wasn't, of course.
I agree. Unlike Mel Gibson, who I think is anti-semitic, I doubt Richards has anything against black people. He was angry at being heckled and tried to push the comedic envelope, with disasterous results.
It was very ugly, but I don't think he's a bigot.