No, he's being raked over the coals because he's not being politically correct.
He probably thought he was being funny with his "nappy-headed hos" comment.
But the touchy-feely brigade is out in full force these days.
I have to wonder how many of the folks who called in to complain were actual watchers of his show. I mean, Imus has a pretty damning history of derogatory comments directed to a large number of groups -- this should hardly be news to anyone. If enough of Imus's actual viewers stopped watching the show in protest over his remarks, then his show would have gone off the air "naturally", but that wasn't about to happen, because his listeners largely feel the same way he does. Why shouldn't he be allowed to cater to that slice of America?