I agree that in fiction (and fanfiction) there is a tendency to make disabled persons as something to be fixed...or pitied. And there is really no reason for it. Yes, I do think that if a character is disabled there should be acknowledgment of that fact...if nothing else, in explaining how they deal with a non-disabled world.

But I think that too many people want a happy ending...and to them, healing (magically or otherwise) a disabled person is how you get to a happy ending.

I once wrote a fanfic for BtVS in which Giles ended up in a wheelchair after a gas line explosion (yes, I wanted it to be non-supernatural-related).

You would not believe how many people wanted him magically healed (I had parts of his spine crushed...no chance of walking again). And they were extremely upset when I told them that nope...he was staying that way. I also showed how he ended up dealing with his disability and having a very full and fun life (including an active sex life).