I think the reason is because I am an actual mintority who is doing the same thing. It's exactly why I relate to the movie despite being a woman.
Edit. Sorry, I was getting hyperbolic. There just isn't much development of her character so it is hard to see what the relationship between her and Ethan Hawke's character is even based on.
> "it is hard to see what the relationship between her and Ethan Hawke's character is even based on."
As implied in the movie he sees in her a person who, despite being a valid, is limited by the fact that she has a disability. The same kind of disability he has. Only she buys in to it and allows cultural expectations to limit her. He wants to "fix her". To show her that she may not be so limited if she has the fortitude to push past her limitation.
Also they probably find each other physically attractive too.