" I (and the OP) am suggesting that the rule could (should?) be changed to be the same as it is everywhere else on the field."
Actually the same rule applies from scrimmage for everywhere else on the field. Many times near any given yd line during a game a scrimmage occurs in which short short yardage is needed and the QB keeps and dives straight ahead. The same congestion is there that occurs at the goal line. Many times in his lunge forward he leads with the ball on top of the pack and fully in his control, and gets pushed back. A 1st down is awarded. He broke the 1st down line plane.
"Gets pushed back" and "pulls the ball back" are completely different. If a player is pushed back, he gets forward progress. If he pulls the ball back on his own, he doesn't. That's how the rule applies today everywhere except at the goal line.
EDIT: Also, if the ball carrier fumbles before being pushed back, it's called a fumble. Again, everywhere except at the goal line.
This calls to mind a play at the end of the 2003 East Division Final, Toronto at Montreal. Marcus Brady was playing for Damon Allen and had the game of his life - in the pros, at least. Behind by a major in the dying moments, Brady ran for the end zone only to have the football dislodged just as he was "breaking the plane". Ouch! I had money on the Argos; it still hurts.