OK, one possession game instead of one score, if that makes you happy. When you are trailing late, you need to reduce the number of possessions you need.
It is not better to find out early, that doesn't make any sense - it's like saying you'd prefer that the other team scores 20 in the first quarter, so you know you have to come back. You can find out if it is a 1- or 2-score game by just kicking the XP. It was a 2-possession game, they scored a TD, and failing to get the 2-pt conversion kept it...a 2 possession game.
I mean, when it comes down to it, kicking the 1 gives you the opportunity to not depend on recovering an onside kick. The alternate to that isn't "you find out early," it's that going for 2 would give us a chance to win with a 2. pt later.