Vick missed too much time due to injury to be MVP IMO.
No player has ever won MVP when missing 3+ games. While there is typically always a first time, the issue is that missing that many games makes it likely that other players have just as compelling or more compelling cases for the award. That is the case here.
Brady's case is more compelling.
Really? Simply because he played more games?
No, it's obviously not that simple. Many other reasons are posted in this thread already. In summary:
[*]Brady has led his team to 12 wins. Vick has led his team to 8 wins.
[*]Brady has done that while dealing with more injuries/turnover to his supporting cast.
[*]Brady has faced a tougher schedule (cumulative opponents' record 99-93) than Vick (cumulative opponents' record 62-63, counting only games both started and finished); of those games, Brady played 6 games vs. teams currently contending for the playoffs, while Vick played only 3.
[*]Meanwhile, Vick's team went 2-1 in the three full games he missed, including an impressive win over Atlanta. Philadelphia is a likely playoff contending team without Vick.
[*]Brady is the top rated passer in the league and has more total yards, more total TDs, fewer turnovers, and fewer sacks than Vick.
[*]Brady is a media favorite and has won the MVP previously, so he entered the season as a preseason contender for the award, which helps.
[*]Meanwhile, Vick's past presumably hurts him with some voters.
Some of these things are examples of why players who miss a few games don't win. It makes it too likely that other players who also have great seasons are able to compile more compelling resumes, given the extra opportunity to compile wins and numbers.