Amen. I know a guy who is an extremely talented programmer, but for a number of reasons currently has a very poor work ethic. While he is able to be considerably more productive than a number of his lesser clued co-workers, he isn't.

And why do you think that is? I've seen too many situations where the reward for being more productive than lesser-clued co-workers was a greater share of grief and stress.

Well in his case it's because he's obsessed with finding the shortest possible solutions to the more difficult levels in the puzzle game Fish Fillets. He's recently rewritten the game's undo/redo system to help him in this.

Sometimes people, even smart people, are unproductive for the usual reasons -- they're lazy/unmotivated or simply just goofing off.

Those smart people can also give you more ideas for things to ship.