I mean, youtube's pretty interactive, too.
Some media lend themselves to constant interaction and some don't. They tried interactive film in the 90s, with audiences choosing outcomes, and it was awful. Film is a storytelling medium, and interactivity interferes with that. I tend to think of good theme park design as sharing a great deal with the philosophy of film-making, with the audience physically moving rather than the camera moving for them. It's one of the reasons I'm not a fan of raft rides like Popeye - the designers give up too much control over the riders point of view. I want rides - and movies - to tell me the most amazing story they can in the most amazing way. When I want to play a game, I'll play a game.