You both raise a good point in that we don't want to see players batting the ball out the back of the end zone to retain possession and try again. To counter that, I would submit two points:

1. I doubt most offensive players would seek to bat the ball out the back of the end zone when a fumble occurred there, even if the rule were different. If they make the recovery in the end zone, it's a guaranteed touchdown. If not, retaining possession may not result in any points. Foregoing guaranteed points in favor of the possibility of earning points on a future play would probably not sit well with many coaches.

2. Have you ever seen a defensive player try to take advantage of this rule by batting a loose ball out the back of the end zone? I haven't. Seems to me that any time a fumble occurs, every player anywhere near it swarms to the ball, as it should be.

I still say the rule stinks. Until the ball has physically changed possession, the ball should stay with the team that had it to begin with. So who cares what I think? Good question.