It's popular because it's a great theme along with a popular IP. Its both of them together that makes it special.
What is with the fascination with trying to say it's simply one or the other. It's a great marriage of theming AND IP. Without either then the area wouldn't be as popular.
People always think they are so much smarter than everyone else. Because surely Bob Iger is completely ignorant of theming. Because he is choosing to go a route different from the one you would take, there can be no other conclusion than he simply doesn't understand the "correct" point of view. It's like that once a year post we get of someone excitedly proclaiming they thought of the perfect attraction..................and they go on to present a Mary Poppins carousel ride that breaks apart into a dark ride. A ride everyone has thought of at one point or another INCLUDING the imagineers.