Why bother making the game good if you're going to rake in loads of money regardless of quality? As people have stated correctly in this very thread, movie tie-ins generally make a truckload of cash regardless of whether or not the game is actually any good. Okay, so E.T. for the ancient Atari console is an exception to the rule, but that game was the pits.

Look at all the Disney games released over the past decade. They're all the same old mix of platform, driving and shooting, and boy, it's getting old. However, why should Disney update this formula and release a half-decent game when the ones they're currently releasing are selling so damn well?

If a game is completely unknown, doesn't have a movie license and has had no advertising whatsoever, then of course it will fail. What surprises me is that the developers of this type of game still continue to release them, even though they must know that they aren't going to make any profit. The mind boggles...