Well, it should go without saying that for an incentive to be effective, it has to be effective. Crazy proposition, I know, so I understand why you might be confused. I mean, for some people, “hey it’s more fun this way!” is all the incentive they need, so they don’t care if the designer tuned anything. They’re happy deciding how many hit points the monsters have and how much damage the guns did. They’re happy “finding their own fun”. For other people, an achievement will do the trick. For yet others, there should be some in-game balance going on.
But my point is that the designers who don’t even try aren’t doing their jobs. They’re leaving it up to someone else.
-Tom