American sports have very strange rules compared to most of the world. Salary caps, drafts, players are signed to the league rather than clubs, franchising ownership.

The results are that there isn't much room to grow the sports. Youth development also suffers, teams have no incentive to develop youth talent, and youth teams are generally pay-to-play, meaning it is hard for the poor to join.

I guess if the sports is not popular in US, this may be the only way of survival though