My assumption is that Anne Robinson's "nasty" act is as much of a fake as many TV presenters "nice" act. It's a comfortable living, more so than other ways of selling oneself.

It's still pretty nasty, and I suspect that it has done rather a lot of harm through people thinking it's clever and funny and OK to bully people they have in their power. "Bad money drives out good" they used to say, when rulers went in for debasing the coinage. "Bad manners drive out good" when it comes to debasing things more important than coinage.