On the one hand, I'm not in a place where I can question the lived experience of your roommate. On the other hand, a sexist-racist heuristic is still sexist and/or racist.
If I, as a Chinese dude, stated publicly that I don't want to date Chinese women because they're hyper materialistic and status seeking (not a belief I hold irl), I would hope that people would speak up and tell me that that's a fucked up thing to say.
Or, to remove the gender and patriarchy angle from it, if I got mugged a few times by people of a certain racial group, it would still be really fucked up of me to claim that I have a heuristic where I avoid people of that race.