> I'm pretty sure that helping to remove a civil right from a group of people can be taken as discriminatory.
Sure, he holds views that some people should be discriminated against, and contributes to political causes advocating that. Lots of people hold those kind of views, and lots of people hold other objectionable views. My objection is to punishing him at work for that, and that alone.
I'm fine with Mozilla employees deciding that they're better off somewhere else, because they don't like their boss for any reason. That's their decision about who they associate with.
I think it's more of a problem when they decide he should be somewhere else because they don't like his opinions, or his political actions. I think that's discriminatory, and a large problem in a free society.
Gosh golly, what's it coming to when right straight white people can't discriminate against unpopular minority groups without facing consequences! It's as you say: minority groups should just quit if their boss might be discriminatory. That will surely end the problem of discrimination.