I find this instinctually ironic. From my reading, he did not imply that the gender bias was nonexistent, but that the political bias was being ignored. And, by asserting your apparent left-leaning bias here, you are only proving his point. In fact, opening up conversation that acknowledges the right in reference to this issue seems to be what he was asking, and what you are not engaging in. I hope this does not sound like an attack on your views, as I myself also identify as liberal and share your views. However, I think we should honor his request to view these beliefs as a potential source for further bias, which I myself am still struggling with.