RMS can (could) make his defense, nobody stopped him, sreened or censored the posts, his opinions are legal.

RMS can't (couldn't) make some of the statements he made and keep his prominent positions.

The issue at hand is not that he was defending his deceased friend. Indeed I think it is very possible that the actual situation was that Minsky was there and declined the sexual advances. That is a story which is out there, I'm not here to judge if it's true or not.

It was the way RMS was defending. Those specific statements are things you "can't" do and - qualifying here - keep a prominent public position, especially when you are making them in a prominent forum in that institution.

RMS shouldn't be charged with a crime, but he did make a whole lot of people not want to work with or be associated with him.