Keep in mind though that the vast majority of rides and attractions at WDW do not have height requirements. If the opposite were true and WDW had very few rides/attractions that shorter children could not ride, then I could see how charging based on height would be justified. Also, there are alot of people who can't ride everything due to health restrictions (myself included), but I still have to pay the same amount as someone who can ride everything.
I think charging by age works better for Disney. But I could see how places like Six Flags would charge by height since there are fewer things very young children can do compared to WDW.
