Okay if your theory was correct then pallet forks would never work.
I know for a fact my tractor was used to lift pallets of stone or at least raise one enough to move them, also I know that a heavy load is best carried low to the ground makes it easier to move and less prone to tip equipment over with weight shift.
All I know is bucket teeth make breaking the ground up so it can be dug up easier, thus making digging easier, never thought it would hinder the lifting or curling of the bucket other then it makes it easier to pierce the dirt and thus lifting more of it. Another way to look at it teeth are only a small area as opposed to the long flat bucket lip, less surface but pierces further.
But you could be right, I have been wrong before, don't believe me ask my wife.