(/s, because on the Internet nobody knows you're a dog^W^Wbeing sarcastic)
...like, I ain't saying I like the guy or anything - he definitely seems like someone I wouldn't enjoy interacting with day-to-day - but I'm skeptical of the idea that having heterodox opinions or being a bit of a stubborn ass should be a fireable offense. If he was outright sexually assaulting people, or abusing a position of power for sex, or something like that, then sure, villainize the guy (and - better yet - pursue criminal charges), but as it stands, it seems like his worst actual offense was being a stereotypical socially awkward nerd.
But hey, if Mozilla doesn't want to associate with the FSF for whatever reason, then that's their perogative. I'm sure they'll stop using GNU and its components company-wide any day now.