One of the things that drives me just a little bit up the wall about disability in pop culture is when creators want to have a disabled character, but don't want that character to have any of the actual consequences of being disabled. This plays out in one of two ways: Either the disability is just there, without any of the attending difficulties, or the disability has been turned into a Super Power. Sometimes, we get both.
I've never seen wheelchair-using Professor X have to actually deal with stairs. He uses his psychic powers to make his wheelchair float.