There's a qualitative difference between making a joke, which probably had no bearing on her actual opinion or position on AIDS or Africa, and actively trying to deny rights to other people. It's not like she donated money to Stormfront.

The equivalent comparison to Eich would be if he made a joke ending with "... Oh wait, I'm not gay" or something.

(And wasn't a lot of the Mozilla thing really a disguised way at getting back at him for JavaScript?)