People are employed on what they contribute to the company, not on their social or political views.
If these employees are such bigots and fascists, that they can't fathom someone having a different opinion to their own, they should resign and work elsewhere.
Mozilla is a technology company with the mission to promote a free and open web. If these employees believed that Mozilla was some kind of political organisation, they are wrong and have been deluding themselves.
Does Eich refuse to work with gay people? Is he suddenly firing people because of their sexual orientation or political beliefs? No. So who is the fascist? Looks like the mob who demand he resign or be fired because they don't like his views.
Marriage equality? So why doesn't the campaign include polygamous families? They exist, they have kids, they even have TV shows, and there has been a cultural history of polygamy around the world for thousands of years until modern times.
The campaign for gay marriage is exactly that, gay marriage, but it is not a campaign for civil rights for everyone, because if it were, it would support the right for polygamous marriages to be recognized.
But he did give money that denied people's rights, so by your (weird, wrong and stupid definition) of fascist he is one. There is no mob, there are a few people and the "demand" is worded rather weakly. I would have expected a bit more of your fascists to be honest.
Please articulate how they are being bigots. Also, how exactly are they fascists? I don't see any of them advocating for the subjugation of individuality or economic freedom for the furtherance of the state. Fascism has an actual meaning, it's not just some mud to sling around.