THE DIRECTOR IS THE ONLY MASTER ON BOARD AFTER GOD! (DITOMOBAG).
He is the guarantee of the global consistency of the vision. He makes sure all the elements of the game contribute to creating the same emotion. His choices can/must be subjective. They may be debatable when taken individually but it is imperative that they form part of a global vision that is clear and consistent.The purpose of this organization was to have an "auteur" approach to game creation i.e. to create a context that gives one person full power to express his/her vision. This specifically made it possible to adopt strong-willed stances without constantly seeking compromises at all costs, which would have been disastrous for a project that claims to be innovative.
For me it is fundamental to have the director embodying the vision of the project: it is extremely rare for a truly original game to be developed without the creative vision of one person (from Shadow of the Colossus by Fumito Ueda to Psychonauts by Tim Schafer or Killer 7 by Gouichi Suda, or also Metal Gear Solid by Hideo Kojima).
--David Cage, creator of the hit game Heavy Rain, via gamasutra.com