Many years ago, there was a passage in Heinlein's Stranger in a Strange Land. In it he refers to humor, using the analogy of monkeys in a zoo. He pointed out that humor is about pain [even puns].

Both Borat and Imus are about pain. Imus is/was a so-called insult comedian and Borat is about putting people up in public and making them twist and turn in a sort of auto de fe.

It is hard to say which is worse. Imus brings out the worst in himself and if you challenge him you are poor sport. Borat holds people up to ridicule for their own behavior--which he goads them into. Either one is a death of a thousand cuts and ultimately makes people feels worse about themselves.

Kaufman fell somewhere between them but the results were similar. After being 'on' with him, people often felt embarassed and foolish if they had any sense.

All three are very effective styles. When they lead to people learning about themselves, they provide a useful act. When they are simply there to pander and make people laugh at the goat while thinking "Am I glad I'm not that idiot" they are simply nasty.