There is a song by Silversun Pickups, called “It doesn’t matter why” that I think nails the feeling of:
It doesn’t really matter what or why we are broken but it’s just the reality and trying to over analyze to “understand” it might not be as helpful as accepting it and working with us.

I think people want to think of it ( any disability) as simple and solveable so that they are comforted that it wouldn’t stop them if they had it.