My argument is: gender itself shouldn't be used as a criterion for group membership.
Did you know that in computer science there is only 17% of students that are female? In the 1950s and 1960s it was mostly women in comp sci and programming. For some reason women just gave up Computer Science and Programming and young men took over because there was a void to fill. Personal computers made owning a computer more affordable and thus learning how to program cheaper as well.
Of course if you follow the news, we are having debates over which bathroom to use for transgender people and then some people are neither male nor female so what to do for that? Maybe a unisex bathroom for a third bathroom choice? I think the same thing is happening to student social clubs now. STEM clubs are mostly male because not enough females take STEM classes and there is no gender requirement for STEM classes but they end up mostly male anyway.