I think your article is great!! I agree with everything you said. This is kind of a pet peeve of mine. I took my twins to Disney when they were babies. Even though changing twice the diapers was time consuming, I would never change them on the train or monorail. I wouldn't change them on a bench either.
You are right... there are bathrooms everywhere. I even found a website that a lady has, where she has listed every bathroom at all the parks and DTD, and exactly where they are located. She even has pictures of the locations and the insides of the bathrooms. I printed this out before we went, so I knew exactly where to find a bathroom no matter where we were.
If we were in line, and a baby needed changing, I would just get out and let my family ride the ride while I changed the diaper. Especially if it was poopy.
When we went in November, I saw a lady change her baby's diaper on the seat at 50's Prime Time Cafe. I saw diapers getting changed on benches at least twice. I also on one trip saw a diaper getting changed on the monorail. I also saw a diaper getting changed at Playhouse Disney on the floor, and it was a dirty diaper, everyone around was moving away.
With so many bathrooms, I just don't know why people don't use them.