Yeah, rape is always rape, but a large majority are committed by men against women, thus making it a crime that predominately targets women, and is predominately committed by men. It's rape, but it's also a crime of power against gender/sexuality. Much like murder is murder, but it also can be a racial/hate crime. (Sorry, just not really sure where you were headed with that)
And to be clear to everyone, I'm all for everyone learning self-defense. You are responsible for your own defense. What I am against here, is the way we teach self-defense of women as rape prevention, and ignore many of the underlying issues.