Definition of a "casual fan" (not mine)...
"A casual fan is a relaxed viewer who follows a sport, team, or entertainment franchise only during big events or active seasons, spending less than two to five hours per week on content without deep-diving into statistics, off-season news, or online community forums."
Sounds like no one on this board, whom you are contorting to reference.
What you meant by that was a fan that you don't agree with, "isn't as good as fan as you", and "needs to find another team". A "hater" in your own words.
Glad I could clear that up for you, Mr. fan who goes all milk carton and disappears when things go wrong (which ironically is a sign of being a casual fan).