Personally I don't think his personal life, and treatment of his wife, have anything to do with him being a feminist. Feminism revolves around to basic principles, for women to be treated equally as a man in all aspects of life, and for their gender not to be their defining characteristic. If he was married to a man, and had treated him in the same way, the feminist argument would never have been brought up. Should his wife be treated differently because she is women, or should she be treated equally? The media coverage would seem to suggest the former.
If he was a woman he would be treated the same. Case in point: Angelina Jolie. She's still trying to recover from her falls allegation against Brad Pitt, everyone hate her, everyone took his side. It's not about gender, it's about being an honest and decent person.
I'm referring more to the fact people are claiming he can no longer be a feminist for the way he treated his wife, as they are not mutually exclusive things. While I don't know much about the Jolie story, people's action don't necessarily have a negative effect on their career. Roman Polanski was convicted of statutory rape, skipped country before sentencing, never served his time and has since won a Oscar.
Roman Polanski never claimed he was a feminist or based most of his fan base on it. But make no mistake, no one forgets about it, and people always ask him about it and it hunts him everywhere. I think that people also feel sorry for him because his fiancee was brutally murdered while being eight months pregnant by a crazy cult.
Yes, you can be a terrible person and create good feminist characters, but Joss Whedon hasn't done that in a long time either. In fact he manage to annoy that fan base with the Black Widow plot in Age of Ulton. It seems like his vision for Batgirl has already manage to anger Batgirl fans, so it doesn't look good. And DC have never been good at dealing with publicity problems or reigning in problematic directors when they needed to. Basing your fan base on being feminist is tricky because they can easily turn on you if you don't live up to their expectations, he should have seen it coming.
Do I understand the message here is that a man who identifies with feminists cannot commit adultery or he's betraying feminism? That a man's personal life may disqualify him from continuing work in his professional life? Bill Clinton continued as President of the United States in spite of sexual misconduct with a young intern working for him. Any businessman or school teacher would be fired for that. I haven't paid much attention to the Joss whedon controversy, and I'm not saying I agree or disagree with letting him keep his job. Just wondering if cheating on his wife is the only real charge against him.