J.R.R. Tolkien extremely disliked everything Walt Disney did, never letting him touch any of his work (which Walt tried to do). He saw Disney as a man who made his success by watering/dumbing down fairy tales for the general public. I think it would be an insult to his memory to take his ideas and put them in a place he himself would never want them to be. His son is very defensive of his father's work, and would surely have a negative voice in any such Hobbit attraction.