None of the parks save MK were designed as "ride" parks. Epcot was supposed to be a World's Fair, DHS was designed to be a working movie lot with an emphasis on shows, not rides. Animal Kingdom is a big and really good zoo. Over the years they've shoehorned rides in because people want rides, but that's been tough because of space, infrastructure and other limitations. If they ever build a fifth gate, I'm sure it will be heavy on rides, but the three non-MK parks weren't meant to be amusement parks, so they aren't.