An article in Slate analyzes the probabilities of each strategy. The probability of the Giants' winning by killing the clock and attempting the field goal is calculated at 98%. The probability of the Giants' winning by scoring the uncontested touchdown and giving the Patriots a minute and a timeout to answer with a touchdown was computed at 88%. In other words, milking the clock gave the Pats a 2% chance of winning, while letting the Giants score gave them a 12% chance. That's a six times greater probability of New England winning the game. Here's the link.
All that is stupid in light of the fact that Brady had an entire game to score more than 17 points and couldn’t do it, so the liklihood of his team scoring 7 more in 58 seconds was not good. Folks should ignore crap like you’re trying to float because it does not take into the calculus the history of the game up to the 58 seconds. Defenses win super bowls. The Ginats’ defense won the game by shutting Brady and company down for only 17 points. How many points per game did the Pats avergae the whole year? ... But not against Piere-Paul & co. defenses!
Without any sort of context, taking a knee and getting tackled at the two makes sense.
If your kicker is David Akers, perhaps it would be foolish to try to score a touchdown.
But to pass up a guaranteed six points-when you're behind with less than a minute to go-in favor of a field goal attempt by a spotty kicker who almost missed two field goals under forty yards earlier in the game is absolute madness, Brady or no Brady.