The problem is that evo psych needs universals to work. Universals means things that match across all cultures. And there are lots and lots of cultures, and even many times more if we include now extinct historical cultures. Women being non-promiscuous is a widely held value, certainly, but very far from being a universal. Very, very far. And women physiology itself doesn't seem to be made for monogamy: women are more likely to be bisexual than men are; women have multiple orgasms and men don't; women can hide their arousal and men can't; women do not show external fertility signs (men either, but men are fertile all the time:) all of these things do not make sense if women are going to be monogamous instead of promiscuous.