Frankly, KitesAvatar, if ANYONE on the board is probably responsible for making .hack (not that anyone is), it'd be Shinsou Wotan. Atleast his name is in the damn credits for Another Birth Volume 3.
Morganna was a program Herald created to maintain the world until Aura awakened as the ultimate AI, then Morganna went berserk, because she gained self awareness, and was trying to prevent Aura from awakening because she didn't want to "die" so to speak.
Morganna's original programming was to raise Aura until she was "born". When she was, there was no real reason for Morganna to exist anymore. Thus she would delete herself. She did not wish to delete herself, but stay alive, so she tried to prevent Aura's birth.