Typically NFL games are played on Sunday here in the US. Lots of people presume they are football experts and talk about what should have happened in the games, typically back at work on Monday. And as the quarterback is in charge of many of the decisions during the game, normally the perspective is what the quarterback should have done. Its very similar to the saying "hindsight is 20/20"; its easy for non experts to critique something that happened in the past letting you know what they would have done, and how they would have done it better.