No I'm not, but perhaps I'm not explaining my point clearly.
You are saying that Brady "had" to throw that pass. I'm saying, respectfully, that that's ****oo. You can say every play in a game is "on execution." If everything was always executed perfectly, every play would work, and we could all sing kumbaya. But obviously not every play is executed perfectly.
So what do you do? You consider the specifics of the situation--where you are in the game, what's the setting, who are the players you're dealing with, etc. etc. In that particular situation, the Patriots had scored 20 points in 3 quarters, putting them on pace to score 27, or about what they go into a game looking to score. They had a first down on the Bills side of the field. While the offense had been a grind all game, it wasn't wholly unsuccessful. You also have to remember that Brady's deep ball, that exact kind of pass, is not his strong suit.
In that situation, there was no reason to throw that pass. It's as simple as that. You're taking a very general proposition--that it's good to take deep shots to keep a defense honest--and using it to defend a really poor play.