To show the normie doesn't have a sense of humour. You can get him to laugh at anything as long as everyone else is laughing at it.
And yes, you can't get him to laugh at anything, no matter how funny, if nobody else is laughing it. Same for music: they like music when it's popular. With music there's a bit of a floor, at least. Absolute dogshit can't get popular...but the floor is not high. The NYT bestseller list doesn't reflect sales, but the normie just wants to buy the books everyone else is buying, which the NYT list causes, so is it really a scam?
The primary point of audiences at comic night is so the few with humour can start laughing and let all the normies know they should laugh too.
Humour is inegalitarian. Being funny makes many very envious. Thus, as Fascism progresses, fewer and fewer comedians will be funny, either because the funny ones get fired or because they learn better than to try in the first place.