His offense had just been denied two tries, after making short runs earlier in the game. Percentages are with the FG, and he wanted a score. My guess is he equated score with momentum. It might have been the right decision, "playing the odds," but I'm a bit of a gambler and would have gone for it. Others have pointed out the tactical ramifications - make it or not, they would have been in good position.
How about looking for the TE on a roll out in that situation?