Yep. Our boy could do around 10-15 in a main queue before completely starting to lose it. He'll lose it in a RAP queue if it is too long as well but people are slightly more understanding in that queue and we know the wait will be shorter.But if the SRQ is shorter than the RAP queue, and therefore requires less queueing than RAP, on similarly level ground and the RAP user doesn't require a companion to ride, the SRQ entirely meets their needs.
I think we need to get past this definition of RAP of 'not being able to queue' - that might describe some, but probably not the majority, of RAP users. Try using "not able to use the main queue line" and you might be closer to describing the majority of RAP users.
Years ago at Alton Towers we saw someone hobble into guest services on crutches, pick up the ride access pass and as soon as they got out of guest services and round the corner picked up the crutches and walked off fine. System was easier to abuse then but it still being abused now would not surprise me one bit, especially with the paper time cards still in use.