Abuse of services that are supposed to be in place to help people who are disabled has been a problem for a long time.  That's why Disney had to change from the original system where parties with people in a wheelchair could just skip the line.  Entitled people with no morals would get a wheelchair for an able bodied person in their party just to skip lines.  Back in the day, sometimes I would see an obvious example of this and it would disgust me.
I won't use a handicapped parking space for 3 seconds to have more room to turn around in a parking lot because, as an able bodied person, I feel strongly that accommodations that exist to assist people with disabilities should ONLY be used to assist people with disabilities.  I am blessed that neither me nor anybody who goes to WDW with me is disabled.  As much as I hate the whole Genie+ and ILL system, I would never dream of trying to take advantage of DAS to shorten my wait time (since I refuse to pay to do that). 
If I ever thought my autistic (pretty severely) nephew could handle a trip to WDW, I would use DAS.  Anybody who interacted with him would immediately know that it was a legitimate accommodation for somebody who has a severe mental disability.