I'm guessing that whoever wrote Darth Maul thought he was really clever for the clear attempt at implicit characteristion. Unbeknown to him that whatever mystery encapsulates Darth Maul is incredibly lacklustre, painfully stereotypical and just downright rubbish. I mean, poor Maul couldn't even get work after the Phantom Menace... Well, except for 'Insidious'.
Then again, there is potential there for a very dangerous threat - but the problem is exposure. Too much would be just as bad as the too little we have, and I honestly think that it's beyond the capability of whoever wrote Maul to balance it correctly. It's just a shame that it wasn't realised.
The real problem with the prequels though, is that they're entirely unnecessary - we don't need to know that Anakin Skywalker built C-3PO, or that Yoda and Chewbacca were friends or how Anakin was discovered. All we need to know to understand and get the most out of the original trilogy... Is in the original trilogy. That stuff aside, and taking the prequels on their own merit... The Phantom Menace is probably the best because there are elements in there that could have made it a better experience, had they just been handled by a skilled team of writers. Mysterious and ancient threat? Check. Shadow games and manipulation? Check. Political upheaval? General intrigue? Check. A decent cast? Check.
Anyway, I voted 'Meh'.
Edit: The implicit characterisation thing, I don't think it succeeded - but it's the only way I can justify the abortion that is Maul as he appears in the film. He is supposed to be menacing, and on that he fails. So, really, he is a bad 'character'.