Okay, I bite, how does a woman using porn contribute to male-favoring norms?
Consumption of pornography, to them, feeds ad revenue (amongst other things) into an industry that they feel is exploitative and degrading towards women. Whether or not this is true is up for debate, barring some kind of large-scale study by a group that doesn't have its head up its ass, of course. But, essentially, they feel that, by consuming typical (straight, cis, PIV, etc) pornography, women are ingraining the idea of male supremacy since, in a lot of porn, it could be argued that the male is seen as dominant.