Mom of 7, I think when they started calling the mentally retarded - mentally disabled it changed people's idea of what they are capable of. The fact that this adult women needs a guardian should clue us in on her mental state. And, as you said, the problem is in the brain, the adult body is still an adult body.
The facility I worked in housed men on one floor and women on another, which caused serious problems. Also, it was located in an high-income area, and (I think) the waiting list was about 10 years or more, so it was considered one of the better homes. Everyone tried very hard to keep an eye on the clients, but because of individual rights, equality, etc. they still had too much free time to pursue their own interest and get into trouble.
There are various reasons parents may look to these homes for their children. Maybe there is no one else to care for them once the parents are too old or ill. Maybe they didn't think it would be as difficult as they found it to be and need help. Either way, the parents are Catholic and deserve to have their religious beliefs respected.
BTW, the high court determined the lower court was out of place with its request and gives it till Monday to justify itself.
Publicity sometimes helps, prayer always helps.
Mom of 7, the people your husband works with are very fortunate to have a Traditional Catholic Man working with them, I give your husband a lot of credit - it's not an easy field to work in for a long period of time.