Ultimately, most baseball games are won because the other team made more mistakes. Exploiting someone else's mistakes is a very useful thing to learn. You hit a short hopper and are certain to be thrown out at first. But you run like hell down the baseline hoping the first baseman will drop the ball. Americans trained in Little League become very good at this.
Baseball is a game of rules with umpires.
Umpires make a lot of mistakes. Generally, over time, both sides get an equal number of bad calls. Playing baseball teaches Americans that while there are rules, there is no real justice. Especially when the umpire is from the other team's hometown. Thus, Americans trained in Little League will learn to bitch and whine about bad calls, and if it happens too often, either fire the ump or change the rules.