The woman who is raped and then becomes a hero is a fantasy cliché that many readers have hated since it became famous with Red Sonja. For decades, I've felt there was something wrong with it, but I've only recently known what it is.
Fantasists who write about rape are suffering from a failure of imagination. If you want a rape in your story, write naturalistic fiction. If you're writing fantasy, find a fantastical equivalent of rape that conveys the powerlessness and degradation of rape. Write about someone hypnotized, compelled, possessed, or otherwise supernaturally forced into doing anything they would not do of their free will.
Fantasy is the literature of literalized metaphor. What would be metaphors in naturalistic fiction—where a train can come at a character like a dragon or a capitalist can drain a community like a vampire or a down-and-out bum can make a comeback like a superhero—are treated as literally true in fantasy. But the symbolism remains: Any fantastical weapon is a metaphor for power, any fantastical obstacle is a metaphor for the difficulties we face in the real world, and any fantastical aid is a metaphor for the things that help us make it through our days. Tolkien might swear on ten thousand Bibles that Lord of the Rings is only a story and not an allegory, but it's a story about people dealing with a power the corrupts those who use it. The metaphors of fantasy may be denied, but they cannot be escaped.
But where is the metaphor in rape? In fantasy, something as mundane as rape is a failure of imagination.
Related: about rape in fantasy and fact
ETA: Someone was upset by my choice of "mundane". I was using it in the sense of the opposite of fantastical, like this dictionary definition: "of this earthly world rather than a heavenly or spiritual one". Fantastical literature has fantasy in it; mundane literature does not. That doesn't mean one's better than the other, just that they provide different possibilities for writers. If you're going to write fantasy, use it to do what isn't possible in any other genre.
ETA 2: Elsewhere, I said:
War is a metaphor for social conflict. Sword fighting is a metaphor for conflict between individuals. But what is rape a metaphor for?
I can’t speak to Patricia Brigg’s books. I haven’t read them. But I do believe there are exceptions to every principle, so if people have written well in fantasy about the consequences of rape, more power to them.
And I must stress that I’m not objecting to writing about rape—I fully believe no subject is taboo. I’m saying that rape is the least imaginative choice that a fantasy writer can make.ETA 3: Shetterly, you hypocrite, you wrote a story about rape!
ETA 4: Why fantasists should write about rape (a response to Why fantasists should not write about rape)