re: This is the nature of American Football: decided by a Call.

IMO, soccer reigns supreme across the globe because the sport is fluid, and easy to understand. During the course of a game, the officials (yes there are crooked refs in FIFA too) don't have the ability to control a game like they do in football.

With American football being a fairly complicated sport with rules, overall game play, game planning, etc, adding officials rigging the game on top of it will make it unwatchable to many across the globe.

A great example of this is one of the games earlier this year that was in London. Don't remember who was playing, but the officials were VERY one sided. This set up a perfect analogy:

You got someone new to football trying to understand the sport. While you are watching the game and explaining all the rules, down and distance, player positions, etc, you got the refs tilting it. Go ahead and explain to this person how this game is being played and not being altered. If you can't do that logically, then....well....