I've always thought that same thing. You're not competing against the world, you're competing within your own nation (sometimes continent). The point isn't whether or not the U.S. could spank another country's team (they could easily, I'm sure), but that it's not a world league. When you play against the world and win, you're world champions. When you play within your nation and win, you're national champions.

The notion can't be that hard to grasp.