Some of them don't. They have different interests other than that. Such as art and music.
Yes, that's completely relevant.
"So disability special interestists are people who have a loveual thing for leg braces or wheel chairs?"
"Yes, but they also like <COMPLETELY UNRELATED STUFF HERE>."
Yes, people with a disability special interest might enjoy making or looking at art (art that's probably related to their special interest, no doubt), but there's neither such thing as abasiophilia music or furry music.