It boils down to six reasons, the reasons that soccer will never catch on in the USA:
1) Low scores. 1-0 is a respectable score in soccer. Really? In Basketball, a 100-98 score is a good game. A 1-0 baseball game is boring. In American football, each touchdown is worth SIX points. SIX! A herculean performance by a pitcher for 0 points in baseball is akin to having a goalie with upwards of 50 saves, but that is an individual performance, and the pitcher's team, of course, can score as much as they want. Maybe as Americans we like individual sports stars that make lots of plays. Wilt Chamberlain. Michael Jordan, Jerry Rice, Tiger Woods. Quantity, WITH quality. But mostly quantity. American Sports are like fast food. Quick. Easy. And yes, we have a problem with portion size.
2) Football has already been taken. No copying of names. We are exceptional, and taking the name for our sport is no bueno. Sure, maybe you named it football first, but that's not the point. You hear that South "America"?
3) Whiny babies get paid. Big time. This might be the exception to the American Fast Food Sports rule above. We allow a Peyton Manning to be a big whiny baby, but he's a Quarterback, and he's surrounded by giants that will protect him. No one will argue that Ronaldo is an incredible athlete.
4) No instant replay, no control of refs. Boys like rules. and the more rules, the better. In fact, once you have established those rules, you have to refine those rules and come up with a complicated set of enforcement techniques to make everyone adhere to the rules.
5) No biting. Seriously. Biting? This rule was initially not a part of this list. But suddenly we have to include it. I can tell you that if Kobe Bryant bit another forward every other game, the benches would clear and he would end up with no teeth. There is no question that he would be booed out of every stadium he played in - including his home team. Biting? I am left with the opinion that biting in sports must be a soccer thing.
6) You can't be fat and do this well. This is very-un-American. Maybe anti-american, in fact. From Football to Baseball to yes, even Bowling, we have heroes with heft. And if success can't come through being overweight in that sport, well that's just not attainable for most of us - hence, un-American.
For these six reasons, the sport they call football but we call soccer will never really "make it" in the USA. That is, unless they change the name, the format, forand allow you to score in some way just by kicking the ball without all that tiring running around.