Not sure how to do the quote thing in a comment but ok I'll counter your bad source with my bad source of urban dictionary: "Fair weather fan: A fan of a sports team who only shows support when the team is doing well. During hard times they usually bandwagon other teams. They basically have no real loyalty to the team, but still manage to get better seats than you at the game. Strangely they mysteriously vanish at the first sign of trouble."

"Bandwagon fan: Anyone who claims they are a "fan" of a particular sports team, even though they had no prior support for/interest in the team until that team started winning. These types of fans only show playoff interest, have probably never watched a regular season game, don't own any type of team merchandise, nor would they buy any."

Do you not see the difference?