Americans like controlled, scientific sports. Hence why all the top sports in the US have deep stats and stat tracking. Soccer, rugby etc is too chaotic for Americans. We want specified times for the offense and defense to be playing. We want the ability to plan and practice plays that can be executed perfectly. Mass motion, chaotic soccer doesnt allow that.
We want our athletes to be larger then life. Thats why we love Shaq, 7'2" 320lbs and can run up and down an NBA court. . Soccer players are great athletes but would be overlooked in a crowd due to a body that doesnt stand out
We love sports highlights. In soccer the only highlights are missed or made goals. In the NFL each game has the potential to have loads of varying highlights
We love superstars who save the day . What can Ronaldo do thats close to hitting a game winning 3 as time expires or leading a team to a game winning TD in the last 2 minutes? Soccer superstars cant shine as often as superstars of American sports. We want a hero to cheer on and dominate games, but thats impossible to do in soccer on a regular basis