As a news organization, they have to be more sensitive to and aware of being closely associated with someone who did something political that many found offensive and over the top, esp against the so-called President. It's that it was the office of the President; not who was the President, that mattered. CNN is already fighting to maintain that it is a neutral organization. Having a host of a big event be someone who did what she did (although it was a joke), would make it harder. It's just not in its best interest. Even if the suits running CNN weren't offended, a news org. has to be picky about things like that.
I hate that that happened to her. It was a pile on that looked like would ruin her career. I'm glad she's made it out the other side of the tunnel.
I don't know that I'd blame Cooper. I doubt he makes the personnel decisions at CNN. I don't get cable so don't watch CNN. But I hate to hear that Cooper didn't say anything to support her.
I remember that Bill Maher was fired from his late night host job on his own show after a comment about the terrorists of 9/11. Comedians are cutting edge. It's so easy for them to cross the line unintentionally.