I met an 18 year old girl with CP. She had one weak leg and one weak arm. She was a really good friend and an amazing writer. I met her when she went to college and lived on her own for a year. Then I went home with her for Christmas and I found out her parents were still cutting her food for her and tying her shoelaces, and they had never let her learn to drive, even though there was no reason not to learn (given one-handed controls), and never made her do any chores. Her ten year old sister had more responsibility. Her parents didn't trust her at all, even though she never did anything dangerous or impulsive.
When she had problems keeping up with schoolwork, and when her parents found she couldn't keep her dorm room clean, they made her come back home. Then they made her live in a group home. She could have been a writer; a really good one. But her parents taught her she was incompetent. I don't know if she'll ever get out of the system.
Parents like that make me really angry. I don't care how disabled your child is. Treating him like he can't do anything for himself, over-protecting, doing things for him, is not going to help him reach his potential. I understand that someone with a disability may benefit from staying at home longer; but doing it like that, directionless, with no plans for the future and no purposeful way to spend your time, is just asking to have your kid feel as useless as you act like he is.