While I don't doubt that some abuse the system, I don't think it is as widespread as people think it is. I would also reiterate that as someone who has used a wheelchair in the park it isn't as much of an advantage as people think. I also see the term GAC being tossed around here a lot so I pulled this info from another disney fan site:
"This is a reply someone got recently when they wrote WDW requesting information about GACs:
Thank you for contacting the Walt Disney World Resort.
We are pleased that you and your family will be vacationing with us and we appreciate your desire to make your visit as comfortable and enjoyable as possible.
The Guest Assistance Card is a tool provided at all four WALT DISNEY WORLD Resort Theme Parks to enhance the service we provide to our Guests with disabilities. It was designed to alert our Cast about those Guests who may need additional assistance. The intent of these cards is to keep Guests from having to explain their service needs each time they visit an attraction.
The Guest Assistance Card is available to our Guests with non-apparent, special assistance needs. However, the intention of this card has never been to bypass attraction wait times, or to be used by Guests with a noticeable service need.
Guests with an apparent mobility concern, such as Guests using wheelchairs, canes, crutches, etc., or Guests with service animals, do NOT need a Guest Assistance Card. These Guests should be directed to follow the attraction entrance procedures for guests using wheelchairs, as outlined in the Guidebook for Guests with Disabilities.
A Guest with a specific need for assistance can request a Guest Assistance Card at any Theme Park Guest Relations location. To accommodate the individual needs of our Guests, we ask that all Guests discuss their assistance requests with a Guest Relations cast member prior to the card being issued. The Guest Relations Cast Member will discuss the available service options with the Guest and provide written instructions for our cast on the Guest Assistance Card. The Guest will be directed to present the Guest Assistance Card to the Greeter or first available Cast Member at the attraction and await further directions for their experience."
If you are still reading, I would also add that as already stated there aren't too many rides left where a wheelchair allows front of the line access. For example, when I went in 2009 in a wheelchair I had to do half of the line outside of HM before they moved me to the accessible entrance near the hearst. This meant we missed the stretching room while "skipping to the front of the line." Not really a great tradeoff if you ask me, since the stretching room as been a favorite of mine since I was a kid. Then when we went last year, after the refurb, with my MIL in a wheelchair we went through the whole queue, into the stretching room and then were taken to the exit where we had to wait about 15 more minutes (felt longer than that though) . The reason being that my MIL has severe parkinsons, can barely walk and needed the omnimover belt stopped so she could ride, because they had just stopped it for a guest we had to wait a very long time. How many people have had to wait at least 15 minutes after the stretching room to get on a doombuggy? Sure doesn't seem faster to me. Another example was POTC. In 2009 I had to leave the wheelchair outside the building, not a big deal because I could walk that distance, we went back in 2012 and I didn' t think my MIL would be able to ride because it would be a very long walk for her. We were told that now you can take wheelchairs all the way down to the boat. I believe Space Mountain is the same way now, but I don't ride that. Toy Story? You wait in line till the stairs and then they take you around the corner to a special loading area, but there is still a wait there. New queue in IASW is the same way. Figment is another example of bringing the wheelchair all the way through the queue up to the ride machine, and we all know how long that wait can be.
Point is it seems like they are designing new queues and redesigned queues to be more handicapped accessible so in the future this won't even be an issue on almost every ride.
And honestly, as some one else pointed out, this woman is stupid for spending $130 an hour for a disabled guide just to get her to the front of the line when she could rent a wheelchair for a week for half the price of an hour. If she really thought that was a quicker way to get on, which it really isn't. Which means the story is probably sensationalized (Post) and just another reason to end this discussion.