A related issue is that a lot of rather bad philosophy has labelled itself 'feminist' as a way of avoiding the same level of scrutiny it would otherwise have (e.g. look up feminist epistemology or metaphysics). [I'm not saying theres nothing good in them, but theres little benefit from lumping it together outside the mainstream debates.]

This damages 'real' feminism because its associated with these, when most proper feminist statements are fairly logically coherent (e.g. the morally relevant things about humans are found in both genders, therefore we should treat both genders as equal).