What's exactly off limits?
1: https://www.washingtonpost.com/video/national/the-thing-abou...
For example, I just searched Google for "comedian pedophilia joke" and the first result is about Louis C.K. doing one during an SNL monologue.
Nothing is off limits in comedy. Plenty of stuff is in bad taste, but as long as the comedian is actually trying to be funny I think most or at least many other comedians will back them up.
https://www.youtube.com/watch?v=rGfDXMnQw7g
https://www.youtube.com/watch?v=ewY3xgqlKPY
https://www.youtube.com/watch?v=ieDNGCIZogA
It's tasteless, yeah. But it's comedy. It's hard to say there are limits.
[edit] It was 18 days after 9/11 at the Friars club roast of Hugh Hefner
Also, I recall a celebrity had a dead crocodile hunter costume for Halloween (Irwin died in September).
[edit] It was Bill Maher.
So it didn't fly?
That's a perfect example of a comedian taking something supposedly solemn and turning it funny. Kind of like when a chef takes an off-cut of meat and turns it into something delicious.
If a comedian showed up to a mic and started making the sort of Holocaust joke that an insensitive person would make after a few beers, they might get some laughs, but laughs aren't the goal--the goal is to have a good set that people like and remember. Their set would likely flop and they would likely not invited back. I dabble a bit in comedy and, yes, I have seen this happen.
This example holds for most sensitive subjects. So no, it is not acceptable in comedy to say anything for the sake of getting a laugh.
His point is that you're allowed to try to be funny about anything, and if you bomb, you pick yourself up and dust yourself off. You should be allowed to make the attempt.
I will agree that the more sensitive a topic is, the funnier you gotta be. The joke should have an insight and good timing and delivery and all that. If you're just saying shocking things for the sake of saying shocking things to try to elicit a reaction, sure, you won't get asked back.
However, that shouldn't be a reflection on how sacred the topic is, but how unfunny you are.