DAS was designed around the needs of autistic kids. They later defined it as "any need that created line anxiety". Before GAC, disability needs were based around wheelchairs. GAC was to service everyone with health issues and had different access types. Those echo were allowed to use a stroller as a wheelchair. Those whip needed only to avoid stairs. And the much coveted those who got the immediate alternate entry stamp.
By adding the return times, Disney made disabled folks wait longer under the principle it was equal access to non-disabled folks. All theme parks do the same now. It doesn't take into account that the stamina of a disabled person may be less or they may be physically unable to do as much.
For instance Magic Kingdom is not a big draw to me because 70% of the rides I cannot do. They are too old and inaccessible. And yet I pay the same for theme park ticket as everyone else.
I have met many fakers along the way. The most maddening ones I encounter in the parking lots. I drive a ramp van and am usually by myself. There's no way I can get into or out of my car if someone Parks or leave something in the hatch marks. Handicapped parking is usually full at the resorts so I end up parking at the far end of the lot next to the maintenance equipment. It's the only way to be sure I can get back in my car. At home I'm parking at the far end buy a dumpster or a light pole when I go out shopping so some idiot doesn't block me out of my car. The worst abusers are those " I'll just be a minute" delivery drivers who will double Park and block two handicap spots.
But I do not have time or energy to brood over the wannabes. My body gives me enough pain and slows me down quite enough to occupy my day. If they want to rack up Bad Karma or God's Wrath, that's their business.
It does concern me that Disney set up a disability program intentionally designed around invisible disabilities that can be easily faked and require no medical proof. But only in that those of us with very visible disabilities are now being openly denied the disability program and encouraged to use the paid option Genie Plus instead.
As for the service dog abuse, the worst abuse I saw was the dog in Epcot clearly not trying to be around a crowd. She was very friendly, too friendly. Easily came up to other people licking them and even stole somebody's hotdog. Now she was friendly but imagine if you had a dog that nipped others. That should get you and the dog banned from Disney parks.