Because they were designed to be decentralised federations, atop the footballing body in each country. More generally, the US is the most capitalist country, whereas the rest of the world does automatically see capitalism as justified, superior or inevitable.
Lastly, football is a grassroots participation sport that is seen by its fans as more of a religion than a conventional act of entertainment. Of course, religion in the US is also often for-profit, but hopefully you get the point.
Lastly, football is a grassroots participation sport that is seen by its fans as more of a religion than a conventional act of entertainment. Of course, religion in the US is also often for-profit, but hopefully you get the point.