Oh, I misunderstood what you were saying. I thought you were saying sexuality was binary. You meant sex as in male female.This comes down to the wealth of language. Can sex sex and gender have different but related meanings? If we are to have understanding and knowledge don't we need a nuanced vocabulary in order to think?
If I were to ask you "What sex are you?" I suspect that you would say male. If I were to ask you what gender you are I suspect that you would reply that you are a man.
The difference may seem subtle but it is important. We use male often in a clinical sense. If I were to say that you are male I wouldn't be saying much about you beyond your biological sex but if we're to call you a man I would be. When I call you a man there is all this extra Paul Bunyan stuff going on. There is a reason that the saying is a "Man's man" and not a "Male's Male".
I somewhat agree with that, although I think sex is not binary there are more than two sex's scientifically but I agree with your setiment.