I used to teach disabled adults and we saw a lot of this sort of thing, the parents considered their disabled adult children like toddlers, we were residential so we got them in house and realised that this 23 year old had never even poured himself a glass of water, so we'd spend all first term teaching them to cook their own food, wash their own clothes, clean their own environment, do their own shopping, just all the things parents hadn't.
Then they'd go home and the parents would do everything for them again because they loved it. No regard to this adult man feeling crappy cause his mom wouldn't let him out of her sight.
One thing I always think about, which did happen sometimes, were those 'kids' who had come to us after their parents died. You have a 40 or 50 year old woman who's never been away from her mother for one minute suddenly thrust alone into the world with zero skills. It's cruel to do that to someone.
And of course, in these groups, physical and sexual assault did happen because they were impaired in some way in understanding and nobody had tried to teach them appropriate behaviour, so what chance do they have! It need education and management to keep everyone safe.