Not sure if you intentionally obtuse or simply don't get it. There is no reason to be a fan of an organization whose main goal is to be making money, but there are plenty of reasons to be a fan of an organization whose main goal is to be better at a sport than other similar organizations.
I don't think the distinction is about whether the organizations make money; the distinction is about entertainment. Professional sports are primarily a form of entertainment. Sports fans are a bit like music fans in that regard. The rivalries in sports can get toxic sometimes, but there's weird snobbery in music and other arts as well.
