Rugby is a fast moving game where plays follow plays in rapid succession. There simply isn't that much time available to dwell upon a given play because (good or bad) the game has already moved on to the next one. When does the fan have the time to grouse and second guess the players and coach? They can't, not if they want to keep up with the action on the field.

It's only after the play has stopped that they can dwell upon poor play or decision making, and by the time that happens, other things have happened to draw their attention.