As the parent of a visually impaired child I find it offensive that people would question why my daughter would want to come to WDW and that the only reason she would be there is because I made her come. Using your point of view, why would she want to go to a movie, watch TV, do anything other than sit in her room.
My daughter is 21 and is legally blind. She walks with a white cane and can reaad braille. However, many visually impaired people do not read braille. Many older people suffer vision loss due to Macular degeneration. At that point in their lives, they don't want to learn braille or their sense of touch isn't sensitive enough to feel the raised dots.
We have been to Disney many times, some when she was very little and still had decent eyesight and more recently where she would be unable to get around by herself. However, Disney is one of her favorite places to visit and she requests to go there.
I realize that to many of us, it is a visual place. However, there is much to enjoy without being able to see the details. One of her favorite rides is Splash Mountain. Maybe she can't see the Briar patch but she can hear the music and there is the excitement of waiting for the drop and wondering how wet she will get. Space mountain is mostly in the dark (I think, it has been many years since I have been on it, though she goes on it). Disney gives her the chance to go on roller coasters, boats, trains, etc. Most of the rides have music. She even likes Mickey's Philharmagic. While she might not be able to see what is happening she can still hear and smell the attraction.
Until our last trip, we had never requested a GOC card. The only reason we did the last time was because a couple of CMs told us we should.
We have had mostly good experiences. It takes a bit longer to board a ride and my daughter prefers to enter Splash Mountain from the exit. The reason is that it is difficult for her to go up the stairs in the dark with all the people. As far as parades, yes we would prefer to sit in a handicapped area. She needs to be as close as possible to see the floats go by, can she see all the details, no, but she can still enjoy herself.
One other place where the GOC is helpful is at HS for Beauty and the Beast. By sitting up front in the middle she can see some of what is happening.
As far as character experiences, she isn't interested in them anymore, though her little sister (8) still is. I have a Disney Visa so we went to that meet and greet at EPCOT. For those of you who aren't familiar with it, each family meets the characters by themselves. No other guests are inside with you. My younger daughter had her picture taken with Mickey and Pluto. She wanted her big sister in some of the photos so I started to help her over. However, Mickey Mouse came over to where she was standing, took her arm in his and guided her to where they needed to be.
BTW, my daughter is graduating college in the spring with a Fine Arts degree in acting. Not only does she want to "see" the show", she plans on starring int it.