In the vast majority of cases these beliefs are completely unfounded. This is because the claims of sexism, racism, greed, corruption and other vices made by the satirist are usually only believed by his audience. And even if this does amount to a large number of people, it's never large enough to have some demonstrable political influence. So in democracies like Australia satire almost never lands a punch on its target. Even if it does, citizens have too many rights in their favor for a politician to seek vengeance on him. He just wouldn't dare.
This is not the case in a lot of other countries, however. In places where tyranny and corruption are widespread, those mocking the powerful are taking huge risks. Take the Iraqi comedians who are poking fun at Islamic State in the show State of Myths, for example. Sure, IS are not presently ruling the city in which the show is produced. But they are certainly aiming to. And they could well achieve this aim if not decisively beaten, and soon. In any case, the show is being broadcast in areas held by the barbaric fanatics.
Considering the Islamists' reputation for extreme acts of brutality, being involved in any way in this production -- and particularly in a visible role as an IS character -- is courageous indeed. I doubt very much that any of the western comics who think of themselves as courageous would attempt anything so daring if they found themselves in a similar situation.