Feminism isn't simply about being a woman in a position of power. It's battling systemic inequities; it's a social justice movement that believes sexism, racism and classism exist and interconnect, and that they should be consistently challenged.
Some people ask, 'Why the word 'feminist'? Why not just say you are a believer in human rights, or something like that?' Because that would be dishonest. Feminism is, of course, part of human rights in general — but to choose to use the vague expression 'human rights' is to deny the specific and particular problem of gender.