In american college sports, there are supporters sections with fans who have their own chants etc and are synchronized in their actions. Also away fans. In european sports, there also are supporters sections, ultra groups, etc.
But in major leagues, like the NBA for example, it seems to me this kind of fan culture doesn’t exist. Why don’t they do it? What is the argument for them for not having organized fan groups in the same way college sports or european sports have?