I don't know. I think Disney parks are really built on nostalgia. So many people bring their kids to Disney because they went to Disney or they grew up with Disney films and TV. Obviously the product itself changes over time and they can innovate but the stories are what's nostalgic. Also its often said Disney is reluctant to make big changes or remove something like Autopia/Speedway because so many kids experience that as a right of passage sort of thing and then those kids bring their kids when they become parents. I know for myself I loved Speedway as a kid and I certainly would want to experience that with my kids whenever I become a parent.
I just don't understand some of Disney's decisions really . .sometimes nostalgia reigns (in the case of leaving around (and refurbing/redoing the track) of an attraction that just doesn't fit anymore (in Tomorrowland Speedway). That attraction space could be totally utilized for something so much better.
And other times new stuff replaces the old that didn't feel like it needed replacing -- (like replacing the Great Movie Ride or replacing 20,000 leagues under the sea with the Little Mermaid.
Personally I like both. I like showing my kids Pirates of the Caribbean and while I miss them not seeing a classic attraction I remember, like the Great Movie Ride, 20,000 Leagues Under the Sea or seeing Mickey's house in Toontown faire, the replacements are just better attractions and will mean more to them (and to me as well since it is "new" to me).
Disney does a great job of making the parks feel new even if you go back repeatedly. But at the same time, there are some things that neeed to go.
A Hollywood studios about the "magic of movie making" was amazing to me in the late 80s. That wouldn't mean much to my son as everything is just digitially done now. But for me, back then, seeing all the practical effects was fun and educating (at least the first time, but being able to experience two of my favorite movies in Star Tours and Indiana Jones Stunt Spectactular made it my favorite park.
While I have nostalgia for those two attractions . .their time has passed. They can go any time now and won't be missed and will be replaced with things much better and frankly I am surprised they haven't yet.