As I said, I think that it's much like teaching a language - yes, I could teach Spanish, but, I'm not a native speaker, so I will certainly not do it as well as a teacher of native Spanish.
I've lived in Spain for a while, I could teach some culture, but I was not raised there, I don't have it ingrained.
Spanish people aren't 'innately' spanish, but their culture is taught from the moment they're born in words, deeds, and expectations. Feminism is the same. A man could teach feminism, but he won't have the depth of understanding, he never can have, because he's never been a woman or a girl, and had the expectations and treatment ingrained in him.
We don't need men's patronage - but feminism is about liberation - and that liberation is from men and males - if we have them teach about feminism, despite not living the reason for it, I think that's wrong. I think that's appropriation, just like if I announced myself an authority on Spanish culture.