To put a finer point on it, it reflects that soccer has a very suburban footprint in terms of who plays it. And everything in the burbs is overmanaged. So you don't get that spark of genius or style you'd see if it was played informally by a broader group of kids. Obviously that gets more sports-oriented kids involved, which means more athletes. Yet it's really the progression of skill where you'd get the benefit.
And just to wrap it around, that's why it's so important for teenage players to get over to foreign clubs. Otherwise they hit a ceiling stateside.