It's a strategy based on the assumption the opponent will blunder. After a certain level blunders become rare, so aggressive play just leads to a poor position.

Inexperienced players like bringing the queen out early because it's a powerful piece -- you can attack many things with it, and maybe even set up a quick checkmate.

As you get more experienced, you realize that it's usually foolish to expose the queen too early. You are giving your opponents the chance to develop their pieces with tempo by making theats against your queen, and while you are busy moving her around, you are failing to develop any of your own pieces.

For example, in the above position, you have all your pieces out and are almost ready to castle. White doesn't have a single piece out, except for the Queen. The initiative you have is worth more than a pawn, practically speaking.