To be honest, who cares if it isn't a well-known property? Take a look at Pirates of the Caribbean, Captain EO, The Haunted Mansion, The Country Bear Jamboree, or even Journey Into Imagination. Had anyone ever heard of the characters in these before they were created? Nope. But you mention Max, Buff, Melvin, Jose, and Figment to anyone who's ever been to Disney World and chances are they'll be able to tell you something about them. This is similar to the "TRON" argument. The movie doesn't have to be insanely popular to warrant an attraction...if the attraction is done well, it will stand on its own to feet and maybe, just maybe, encourage the people to rent the film later. And as another example, "Dinosaur" wasn't a big movie, but it has its own attraction. Say what you will about it, but it is popular (of course, that may have more to do with the lack of attractions at Animal Kingdom, but that's a whole different argument).