You're so close minded its pathetic.
What don't you get? Most Americans are raised with Baseball, Basketball, or American Football. That's what they grow up with and that's what they grow up liking.
You just expect everyone to dump it all and start following football? Be real. All three sports have big followings its just the way Americans are.
Although, imagine if USA really threw away all their sports and dedicated themselves to football? They would be a mass powerhouse and would school the likes of England the way the Germans did in South Africa everytime.
Would be a mass genocide.