I honestly see her point in the game as pointless. First, because she didn't play as much of an antagonist role as she played in the first Kingdom Hearts game. Second, some of her 'evil plots' were kind of trivial, such as turning Santa Claus into a Heartless and going back in time to get the Cornestone of Light in order to fill the castle with darkness. The Organization played more of an 'evil twist' than Maleficent or Pete ever did. At least, some of their plots ended up working, such as going to 'Land of Dragons' and turning one of the guardian dragons into a Heartless and having Sora kill it to release it's heart. Last, Maleficent and Pete seemed to be helping Sora whether than defeating him.
On a side note, I think it's ironic that Maleficent doesn't know that the Nobodies are apart of the Heartless she controls.
It would have been interesting to see Maleficent and the Organization working together to turn Sora into a Heartless and capture Kingdom Hearts, because both of them had the same goal and Sora and his friends were a constant hindrance to both their goals.