Repetitive elements in games (e.g., grinding) make players feel like they've "earned" their triumphs. Making a game take a long time to beat seems like a cheap way to make players attached to their progress in a game. A better way to make players attached to their progress might be to a) make gameplay really difficult, b) create engaging characters, or c) have players come up with their own story.
Making gameplay difficult doesn't have to make a game frustrating; I think Portal's puzzles are sufficiently difficult to make players feel smart and that they're really learning something (they're learning to think of physics in a different way). I'm sure there's a way to effectively teach more complex tasks through games, and I think learning is a ritual worthy of repetition and the challenge is enough to make it interesting. Adam and I have long discussed a kanji-learning game where instead of pushing A, you're reviewing kanji through flashcards. You can still get the boring/comforting thing, but maybe with a bit more brain involvement (also, if you want to help make this game, I only know so much about computer art).
Creating characters that you care about can only go so far. It's usually only part of the picture that makes a game addictive, and loving or hating characters seems to effect some players more than others. And if there's a character everyone likes, it only makes ending the game more painful (but impassioned fans make for good discussions?).
The last option, having players come up with their own story, is the emergent gameplay that characterizes Rohrer's art games (you're imagining the story based on what you're doing; no one is telling you in words what just happened). It feels different from playing a game where the story is in your face. It feels like you're doing the story instead of it happening to you. I agree that emergent narrative is one way to use video games to tell a story that no other medium can replicate. The types of games with emergent narratives are fun to explore and figure out their rules. But sometimes all I want is an interactive story that someone else made up. I would, however, like to see a Dwarf Fortress that is a little more user-friendly.
