OK...I'm going to break ranks and agree (somewhat) with what I think you're saying. While I generally support gender studies programs and gender studies, I do hear lots of shade thrown on the notion of "categorization" of human beings. I typically start to try to argue if I think it advisable; sometimes it's not. But at a very basic level, human reasoning works by categorization (technically, by establishing sets)--you cannot think about anything without first categorizing it. That includes human beings.
Now opponents here have a point. Human beings are so complicated that categorizing them can be dangerous. We may well think of a man as, say, heterosexual, even if he secretly fooled around with a random guy after getting really drunk one night, and occasionally has momentary flashes of homosexual fantasies, but is still really turned on by women. But by putting him in that category, we are failing to capture some truth about him, and if society constructs acceptable roles on the basis of the category, we may well be causing this man secret pain for no reason.
The above is a simple case, but is an example of the kind of thing in which genders studies people are interested, and is also an example of the foundation of the discipline. But that said, to think about such cases (and many much more complicated), they still have to be categorizing human beings. To get a tad more technical, we could extract from the above example what is called a conjunctive definite description that, for the most part, functions like a name (names like "homosexual," "heterosexual," "male," "female," etc.), and that conjunctive definite description names a category.
