SPL's built on Chinese ideas they've had for their football leagues. Some euro players went to China but their league wasn't good so it's failed. SPL isn't like them they're trying to be competitive. They've made the SPL famous because they want to host the football world cup.
To be honest the difference is made by some clubs in the Saudi Pro League investing a lot of money, meaning they have bought many European Player so we think it's because of them that this league is more popular than China's. The steps they have taken in football in an increasingly dramatic way really surprise us because they are now willing to pay a lot of money to keep a player like Ronaldo. At the moment, it seems that the Asian super club is building on their success at the moment as they have brought good performances through many Latin American players in the Club World Cup. In fact due to the popularity of this league, Al Hilal now has many Brazilian players who were able to score goals in the CWC tournament against Manchester City. Maybe because of all these players the SPL can become popular.