Labels for gender and sexuality are so much more than simple political identifiers.
People who actually use them for themselves experience them as guideposts to finding out what's going on inside by seeking out other people's experiences. To us, the labels are no different from "nerd" or "musician." I would still find them useful even without a vast social and political movement hell-bent on making my world as sad and empty as their own.
Identity labels are fundamentally about making space to explore. "Musician" leads to all kinds of places, like grungehead, or rondo fanatic, or furry rave DJ. Why people get so up in arms about identity labels when it comes to gender and sexuality is beyond me, and I've already written too much here to start speculating.