If you're down 14 late, it makes mathematical sense. 2 pointers are successful about 47.5% of the time. 1 pointers 95%.
If you score a TD and go for 2:
47.5% of the time, you'll have 8 points. Now a TD+PAT (95%) will win the game.
52.5% of the time, you'll have 6 points. Now a TD+2pt (47.5%) will tie the game.
Calculating out:
Make XP on first TD:
14 points: (95*.95) 90.25%
13 points: (.95*.05) 4.75%
Miss XP and forced to go for 2 on second TD:
14 points (.05*.475) 2.375%
12 points (.05*.525) 2.625%
Tie game: 92.625%
Lost game: 7.275%
Make 2PT on first TD and therefore kick PAT for the win:
15 points: (.475*.95) 45.125%
14 points: (.475*.05) 2.375%
Miss 2PT and go for 2 on second TD to tie:
14 points: (.525 * .475) 24.9375%
12 points: (.525 * .525) 27.5625%
Won game: 45.125%
Tie game: 27.3125%
Lost game: 27.5625%
Going for PATs will at best tie the game for you. Going for 2 gives you a greater than 45% chance to outright win and greater than 72% chance to do no worse than kicking PATs. Is a ~45% chance to win worth risking an extra ~20% chance to lose? Yes, yes it is.