Because Rodgers currently is the best quarterback in the game. Brady is not the quarterback he once was even though he won a Super Bowl last year. For example, in a number of Brady's games he didn't even throw a touchdown. The Pats instead won a number of games through their running game. Also Brady has the shortage yardage per pass of basically any quarterback in the NFL, also not a good thing. And Brady's stats as of late really haven't been spectacular. That's partly why Belichick had Brady take some major pay cuts. Brady is nowhere near the top QB pay anymore of over $20 million. He's now around $8-9 million.
Brady does not deserve the credit for that Super Bowl win. Bill Belichick, the Pats rushing game and the Pats defensive secondary does.
Just because a quarterback's team does well doesn't mean the QB is doing well. For example, Rex Grossman made it to the Super Bowl and he was one of the worst quarterbacks of all time. Tim Tebow couldn't hit the broad side of a barn with his passes and his Broncos made it to the playoffs and even beat a horrible Steelers team in the playoffs. So should we say that Tim Tebow is better than Big Ben because he beat Big Ben in the playoffs? I don't think so!
Don't forget that the Pats lost to Rodgers and the Packers in the regular season. And Rodgers far outplayed Wilson in the playoffs. It wasn't Rodgers fault as to why the Packers barely lost to the Seahawks in the playoffs. And if you think Brady is so great because he beat the Seahawks, better get off your high horse. The game was out of his hands at the end of the game. All the Seahawks had to do was run the ball 1-3 times and they would have won the Super Bowl. They had the time outs. There was no time for the Pats to return for a score. The game was all but the Seahawks. The Pats should thank former Pats coach Carroll for making a huge mistake and passing the ball and for that no-name Pats player for making an unlikely interception otherwise we'd have hear Pats fans bawling again and making excuses once more for why they didn't win.
To me, Brady gets far too much credit and Belichick does not get enough. I'm not a fan of either the Packers or the Pats. Just calling things like the facts show.