Somethings to consider....playing games is great and nothing can replicate the in-game experience.
However, if all you do is play games, certain aspects of a player's game suffers. For instance, the first thing to go is defense (and yes, I realize that baseball is more and more a pitching and hitting game). If all you do is play games, when do you practice fielding? hitting a cutoff man? turning a double play? bunt coverages? The answer is you don't.
Another aspect that gets lost if all you do is play games is throwing. I'm not talking about pitchers ... they always seem to get their throwing in. I'm speaking about position players. Typically, if all you are doing is playing games and not practicing, pre-game warmups will often be the only throwing a player gets unless he is a truly diligent player and shows up early to get his work in. And, if they are throwing only before games ...make sure outfielders are throwing outfield distances. Too often, I see outfielders throwing 90'-100' (maybe) in warmups and never really throw outfield distances (200'+). Just an opinion.
Playing games is what it's all about. But, practicing and working on specific skills is critical. It can be great playing lots and lots of games, but often it leaves no time for the player to really develop and truly learn the game.
You see more and more teams (and players) who go from tournament to tournament, showcase to showcase, and you wonder when they ever get time to work on their game.