I have friends with a very severely disabled 19yo. She needs 24 hour care and will never be able to live even semi independently.
She lived at home with her parents until she was 17 when she began to attend a residential school during the week.
She now lives in a residential unit attached to the school and goes home once a month.
Her parents made the decision to send her to that school because her existing school simply did not have the knowledge or facilities to cater for her properly (they live in the wilds of Scotland so no other local options). She absolutely thrived at the new school - the change in her was huge and she made more progress in her year there than she had done in the previous 5 years at her old school.
They decided to keep her in the residential unit because she was 19. If she was NT she would most likely be leaving home to go to Uni/get a job (as her brother and sister did) and they felt that her disability should not deprive her of that. Where they live has very few options for disabled people and they felt she would be very disadvantaged if she had to stay in that environment forever. She is so happy in her new home and it has meant her parents have more freedom than they have had since she was born.
I think residential care is an option and should be an option for all parents with a disabled child, both for the child and the parents' sakes.
My friends have had 17 years of broken nights and constant care of their dd. As they get older they are less able to cope with broken nights and the physicality of caring for her - changing her nappies/pads, dressing her, feeding her, etc. At some point they will not be able to care for her any more.
It's not about 'dumping' her, or burdening the state, it's about finding the most appropriate care for her needs.
Just because fate meant they had a disabled child should not mean that they also have to give up the rest of their lives to care for her. The same goes for every other parent with a disabled child.
Residential care should be an entitlement for every family. An NT child will eventually leave home, why should that be different for those parents with disabled children? It's not their fault that something beyond their control means their child can not do that. It would be very wrong if they have no option but to give up the rest of their entire life to care for their child.