I presume they are taking federal funds, but I still don’t see how or why that should pertain. I’d personally do away with the excesses of the ADA and with federal funding for many, many things. But the idea that a social service agency can’t provide any government-funded services to anyone unless it provides the said services for everyone seems particularly baseless to me.
The ADA has created far more issues than it solved. Even at that there has to be practical limitations grandfathered in. For example you can't make a 100 year old structure such as a school or courthouse meet ADA standards.
At the same time the ADA should also be written so families in difficult situations have legal say. Let me give you a quick example of what I'm saying. Suppose you are given an antidepressant to help stop smoking. Suppose due to an adverse reaction to that medication your behavior becomes severly pyschotic. Do you not believe your spouse should be able to sign for your treatement the same as if you were unconscious from an accident? The same hospital in a state that allows you to sign surgery consent forms for spouse will by law deny you any say in mental health treatment of a spouse or your adult offspring.