That is odd. We have stayed twice at Art of Animation and have never had any complaints with the transportation.
Leaving the resort to head to the parks, we never had to wait more than 10 or 15 minutes for a bus, even during busy times. And we never stood on rides to the parks that I can recall.
Coming back from the parks depended on the time of day. If it was right at park closing, then yes we sometimes had to wait longer. The only time I can recall having to wait past the second bus, though, was one night immediately after the fireworks at Hollywood Studios. Other than that, we always snagged either the first bus during less busy times of the day or the second one if it was at closing time.
No, it's not being on the monorail line, but as bus transportation goes, we didn't have any issues.
That's one of the reasons we love the family suites at Art of Animation. They do not have balconies but they have interior corridors. No exterior room access. And, remember, even the moderates are exterior access and no balconies.