Don't understand the reasoning behind the two point conversion

The game was decided by 3 points not 1, If you feel your odds are good at the 2-point conversion there is no reason not to go for it earlier as opposed to later (where the score differential warrants it). This holds true even when you expect both teams to keep scoring at pace.

When you go for it early you can still go for it again if a new situation warrants it. What you cant do is decide to go back and go for it in the first half when you are in the second half.