(From somewhere irrelevant in Asia, sorry if my English is bad)
Top 5 league "natives" (if they actually are, no way to verify that lmao) are the most notorious for complaining about tourists/ foreign fans, calling them fake and whatnot. European football are the ones that I followed more recently (and the last), so I was rather surprised by how much complaints there are online about foreign fans and tourists, calling us bandwagons, glory hunters, or whatever, which is rather weird considering the Japanese and Koreans are rather welcoming with their baseball/sports (first sports games I've physically been to), and they aren't really known to be most hospitable with foreigners. Americans are pretty welcoming with their sports too, and would be glad to have you in their fanbase even if you bombard them with questions (from my experience).