If someone using a tactic in bad faith means we can't use the tactic any more, we're going to be in a lot of trouble. People talking about things they don't understand and being in need of correction goes a bit deeper than "well, Holocause deniers ask questions too!".

Stallman is not a serial Holocaust denier. He is a software philosopher.

And insofar as he is an agitator, on most of his pet topics time has proven him to be right rather than to be a troll.