The importance of using person-first language can hardly be stressed enough. Placing the person before the wheelchair, cane or speech difficulty accomplishes two things. First, by stressing the person, it emphasizes inner qualities that anyone might have, and de-emphasizes physical appearance. It also normalizes the disability by sending the subtle message that a disability can happen to anyone. Compare that to 'wheelchair person' which has sort of a space-alien feel to it.
Language affects attitudes.
Legislation defending the rights of the disability community might be easier to enforce if everyone saw the person first. The phrase 'everyone's disabled in some way' should not be excused either. This is an error in logic known as equivocation, or the changing of a term's definition in midstream. The person who does this usually finds the disability intimidating. Reducing the seriousness of the disability makes it easier to handle.