I think there is plenty of scope for hilarity without personal cruelty.
This is obviously grand as an aspiration, but it doesn't seem to be borne out by the evidence. 
So many comics either make jokes at other people's expense, or make jokes at their own expense. You can't make jokes at your own expense on a current affairs programme, so you're going to mostly make jokes about other people, or about "events". Producing stand-up material about "events" is going to involve generalising ruthlessly about groups of people until you've got something funny, whether it's about conservatives, pakistanis or nuclear submariners. Most of the generalising is likely to be problematic for someone you're talking about if they aren't laughing along.
I'd be delighted to have some examples of comics who do sets which don't involve either personal cruelty or prejudiced generalisation and don't basically talk about themselves, mind.
