I find it very uncreative that they don't create NEW IP in the parks and let the creativity flow the other way to movies, merchandise etc. They used to do this (i.e. Pirates, Haunted Mansion, Space Mountain etc.). Everyone already knows the major IP they are jamming in the parks now. There's nothing wrong with using some of it to create new attractions and merchandise; however, it would be far more creative to let the Imagineers develop new IP that could be the basis for new attractions and merchandise. Who knows what kind of revenue could be generated from their studio business with new movies etc. based on this IP? You would have creativity flowing both ways.
It's not surprising, on the other hand. If you look at Hollywood, for the most part, they are petrified of taking any risks. So many sequels and reboots etc. The studios are only interested in what is guaranteed to be a smashing success. I get the business side of it, but I don't find it overly creative. I stopped going to Marvel movies about eight years ago because I got tired of them. Same for Star Wars- I'm a fan, but I didn't go to all of the movies in the theatres. For both brands, I thought there were too many movies, and I didn't find the stories or theatrical experience compelling enough to spend money on them after a while. Frankly, I got tired of the franchises.
Sequels, reboots and existing IP have their place- no doubt. But some originality in the parks would be a nice change IMHO.