I think it's more an issue of context. I'm not an expert on this, but I think violent, forcible rape is not the norm. It's more a perversion of the position power of a trusted adult. Physical self-defense skills aren't much help with that, unless the person recognizes the situation for what it is and goes into fight mode.sometimes you gotta do what you gotta do.
I have bashed people on the job I have know and even liked. It kind of sucks.
Of course, if we're talking about forcible rape of an adult (or near-adult), the physical skills do apply. There's still that violation of position power that seems to put some into shock.