The QB is the closer on the team.. Throughout the normal course of a game, any combination of positions can carry you to a win. But when it ends up with both teams having equal/close scores at the end of the fourth.. It is ALL put on the Q to carry his team to victory.
Flacco got kinda lucky with that Denver game.. Bombs that his receivers came down with. But he continued it and executed in every following game. He's not 'elite' unless he can show the ability to have stretches like this in the following years.
But romo sure as hell wasn't going 11-0 td/int