This is the problem with many people who espouse a "cause", on the left or right.
Marlon Brando was one messed up individual, but he had talent. He was perfect in "Streetcar" (I don't think Vivien Leigh cared for him too much) and in "On the Waterfront", and whatever went on behind the scenes of "Guys and Dolls", I thought he was a very sexy Sky Masterson. I thought "Apocolypse Now" was pretty stupid. But in "The Godfather", he was...well, what can you say? You completely forget he's Marlon Brando and totally believe he's Don Corleone. That's the mark of a great actor, IMO.
I'd much rather remember his good film roles and just forget the pathetic, self-absorbed weirdo he was in real life.
I think that about almost every actor and actress I like.