There's this thing in comedy, especially brutal, cynical comedy, where no one is safe from harm. As I said before, everything and everyone can be the subject of a joke, satire or parody. It's also the first line of defense that people bring up against critics of South Park, Team America: World Police, the Grand Theft Auto games and similar cultural products that leave no political side, no gender and no ethnic group unmocked. The basic attitude is: nobody should be exempt from criticism and comedy.
Basically, I agree with this. It is certainly miles better than comedy that, out of ignorance or malevolence, singles out groups of people that are relatively powerless. A good and often-used example is making a joke about rape that rapists will think is funny but that degrades victims.
Some would argue that comedy that singles out white people, the rich, or heterosexuals also falls into that category. It might, depending on the circumstance, but the fact of the matter is that these groups are 'the norm' and hold a lot more sway in society than other groups. As a group, they tend to be fairly well insulated against prejudice and discrimination.
That's what makes the 'everybody is shit' comedy a little disingenious sometimes. Mocking everyone and everything is all well and good, but it doesn't level any playfield. It keeps the status quo as it is. Everyone is stereotyped, yes, but some stereotypes are more harmful than others.
'Everybody is shit' is another way of saying that the truth is somewhere in the middle, which is certainly not always true. There is no middle ground between the Ku Klux Klan and the Civil Rights Movement, for instance. There's no truth to be gleaned from taking a position in the middle between climate change deniers and environmentalists.
There was a case in France, recently, where an advertisement for students was pulled because it was 'sexist', while it clearly stereotyped everyone involved. Did censors go overboard on that one? That's a debate in itself. But it's also a fact that debasing everyone isn't going to take care of a lot of social progress. An increasing objectification of men, for example, has led to a greater number of boys developing eating disorders in the past two decades.
The above is why I maintain that social progress is not about taking away privileges from everyone that has them: it's about bestowing them on everyone, and that's not the same. So, treating everyone like shit may sound like the ultimate in democracy, but at best, it only serves the status quo, and at worst, it ends up with everyone in a worse position than before.