As a premise, Cavemen isn't that bad. Mullets was just horrible on every conceivable level. I didn't get why UPN felt mocking their top fanbase (wrestling) was a smart move.
Cavemen could be decent with better writing. I'm not so sure why this is supposedly controversial. You would have to make a big stretch to call this racist and even so, it's pretty tame compared to most network offerings. It's not an embarrassment to television, it's just boring.