I've had conversations with folks about this (including AVP, who co-authors the Theme Park Access Guide here).
I think "special treatment" is when the city of Berkeley gives people with handicaps *FREE* parking in metered lots instead of just setting aside some metered spots that require ADA placards, because the city thinks people with handicaps are somehow inferior, and are not capable of being self-sufficient ("Oh, you can't walk. You poor thing, because you are handicapped, you can't get a REAL job, so you don't have to pay like everybody else"). What folks want is to be treated like an ordinary person -- no better, no worse.
[This goes against the philosophy of a good friend of mine, who thinks persons with disabilities have a hard enough life, they should be given every break possible. She must think people like me cold-hearted and cruel; I in turn, think persons with handicaps don't need this kind of ill-placed pity charity.]
The issue of using an SA pass in the park is a health issue. It's the same thing as having handicap parking spots near the building entrance. What would be "unfair" would be if persons with handicaps were allowed to enter the park for free because of the mere fact that they have handicaps.
Part of the problem with the park is that the queues were not necessarily designed with handicap access in mind. Some attractions, like Indy, allow you to stroll with your wheelchair through the bulk of the regular queue.
I understand some parks have folks wait in a seating area near the front of the queue until their party meets up with them after waiting in the queue. That is a satisfactory solution as well, and may help keep the complaining from the able-bodied to a minimum.
Here's a question: Now that the Federal government has declared obesity as a medical "handicap" that allows individuals to seek tax deductions, can the medically obese (defined as weighing 20% or more than the ideal weight for the person's height) demand SA passes at the park? Next time you go to the park, take a look at the average park-goer. [and if you've met me, you KNOW I am not a matchstick by any stretch of the imagination!]
Tony -- you are far too polite a person. If I needed to use a wheelchair on a regular basis, I would probably say something like, "Let's you and me trade. Take my wheelchair... and I'll time you while you go to the restroom without using your legs!"