I have seen clips of the Apprentice on different late shows. Everything in that show was disgusting. But most of all it was Trump himself, the way he talks, accent, everything. He is a disgusting pig, no offence to actual pigs.
What I remember is that Trump hardly even showed up in his own show. Short appearance in the beginning (and not always even that), sitting at a desk at the end and uttering his tagline, "you're fired".
(I never saw the celebrity variant though, maybe that's the difference.)