The one thing we have to realize about plays is that they are all situational.
Calling an actual play which involves moving the ball exposes you to a possible steal. Giving up a layup in a tied game is a game-set-match for Miami.
On the other hand, if you run a Pierce isolation, you either win the game, or you go into overtime. So the reward is the same, but the isolation is a low-risk play in the sense that you can't really lose the game.