A theory for people who didn't like this movie
I'm sure a lot of people were attracted to this movie because of the big names in it, and maybe their favorite comedian from TV/movies is in it. For a lot of these viewers, the TV/movie persona of a comedian is the only one they have ever seen.
To get seen on TV, such as Letterman or another late show, a comedian almost always has to submit their jokes ahead of time for the show staff to review; the staff will send back notes with what they can and can't do (obviously they can't say anything like in this movie). Their jokes are then watered down, or cut out completely, until the point where you're not seeing who the comedian really is.
The set that they perform on TV has been so carefully crafted, usually over a year working out the material in clubs to see what works and editing what didn't work, so by the time it gets to you it seems like a masterpiece.
So, what's happening is that you think this comedian is some kind of classy guy. He wrote funny jokes, so he must be smart, and he doesn't say any "bad words". He's so sophisticated that in your eyes he is an aristocrat, and seeing how he is backstage hanging out with fellow comedians has destroyed your illusion.
Maybe?