I don't think you understand how popular soccer has always been, everywhere.
The last FIFA census estimated that there are 265 million people playing in organized games with 5 million referees. We're not even talking about pickup games - which is what the research in your link is about (I'll ignore the quality of research methodology for now) - we're talking about organized leagues. The number of people who play pickup soccer games is much, much higher.
The last FIFA census estimated that there are 265 million people playing in organized games with 5 million referees. We're not even talking about pickup games - which is what the research in your link is about (I'll ignore the quality of research methodology for now) - we're talking about organized leagues. The number of people who play pickup soccer games is much, much higher.