I'm going to have to agree with Jed and Frogio here. While he certainly wasn't a credit to white people, most black rappers aren't credits to their race either. There is no reason to feel ashamed that Vanilla Ice be a white rapper.
If that sort of thing were the case, shouldn't blacks feel ashamed of people like Jackie Robinson and Buck O'Neil for playing what had otherwise been a white game of baseball? Doubt it...