If you think about it most of the world just chooses a single sport (tends to be soccer) and runs with it, and every other sport is some minor thing in their country. The only other countries I can think of with similar diversity in the sports they play and watch are australia ,where they have aussie rules, rugby league, cricket, soccer, and basketball, and canada, which is probably due to inheriting a lot of american sports culture.
Why do you think american sports culture is the way it is where 4-5 leagues make good money and many people watch all of them?