To be completely clear I have never used DAS and hope I never have to.
I understand the potential immense advantage that DAS users can have by allowing re-rides on attractions, especially E-tickets. I also understand that this can affect operations for that particular ride.
However, I have a moral issue with disallowing access to something for a disabled person while allowing access to the same thing for a non-disabled person.
As a non-DAS user, I have the ability to wait in multiple hour+ lines a day if I so choose. I may not want to, my kid might be screaming there head off, I might be bored, hungry, and need to go to the bathroom, however, nothing is stopping me from doing this physically or in the Disney rules (for any non-VQ ride). This does have a high opportunity cost for me as every minute I am in this line is a minute I can't do anything else in the park.
Denying the DAS user the same ability as a non-DAS user feels morally wrong to me even though the opportunity cost of doing it is much much lower.
I have no legal background, but I also wonder if Disney would be worried about denying a person with a disability from doing something that a person without a disability is able to do (Even if basically no one does it).