I like Wanda, but the Cos is right on target. Anyone - black, white, brown, whatever - who refuses to speak and write properly (apart from pro athletes and rappers, of course) - has a very slim chance of success in this world. It's really not so hard to learn and apply proper English.
Black humor has always been crass, politically-incorrect, and filled with profanity and sex. Cosby is right on this issue but he needs to leave the other comedians alone. People like Chris Tucker and Eddie Murphy in the 80s and Pryor and Redd Foxx in the 70s were DA BOMB! Even Cosby himself used to be a bad-ass. Rent Murphy's "Raw" and see him rake Cosby over the coals with that voice of his. LOL