Baxter loves IP. I think because he doesn't excell in telling a story. Thunder works, beautifully so, but the whole story only became clear after decades. He found no good way of telling it on the ride (arguably intuitively the rider understood nevertheless, which is even better). At Imagination he used original characters, with not even an established physical universe to draw from as with Thunder, so he felt he needed to open with their introduction, the rather static 'origin movie' first three minutes Splash' does use IP, so now again Baxter doesn't explain anything, and the attraction story is exceedingly difficult to figure out. The only times he truly succeeded in telling a ride's story in an efficient way are indeed with Indy and Star Wars - drawing on well defined characters and universes.