Yeah, the apple ghost buttons are a dialog with the user. They say "you have seen this situation 1000s of times, and are tired and bored". They slip into the background as your finger autopilots to the same spot it always goes. When the action becomes rote, the button becomes tacky.

On, say, a kitchen stove, I find the same minimal design frustrating, because I don't use it enough to be familiar, and I want 100% certainty.