Unless there's someone more interesting. And saving the world is pretty interesting usually.
We'll have to disagree on this; I see no particular appeal in saving the world from yet another completely dehumanized Dark Horde.
Yeah, seeing someone doing it would could suck if done badly, but no one's saying you need to play as The Savior's stableboy. DAII and KOTOR2 (or Mask of the Betrayer if anyone played that one) are good examples of how it can be done: you do have a huge effect on the game world, but you're not playing for that effect's sake, instead you are driven primarily by more personal reasons - which makes the game more engaging, at least for me.