I think it is primarily symptom, though it is part of a feedback loop. Porn is a way of helping people to define their sexuality, and if that definition comes along with captions like, "these brazen sluts are hungry for your cum," that can't help but affect the way that male consumers of porn relate to women around them.

So i think there is a healing role that non-misogynistic porn can play in the sexual healing of our society. It would not be a "strong" catalyst for a change, in that we'd be able to see its effects rapidly, but i think that the more of it we have available, the better.