I think we need Bandwagoners... to me someone gets on the bandwagon when they start to take an interest in a team (eg. Parramatta/Melbourne), a sport (eg. Soccer courtesy of the Socceroos World Cup success or Rugby during the 2003 RWC), or anything else for that matter when it/them is/are popular and everyone else is talking about it/them. This term transcends the sporting arena and can be seen in everyday business (eg. iPod), music, politics, etc.
The positive here is that a percentage of bandwagoners stay on... they get hooked, they enjoy what they see and overtime they become more traditional supporters.
Personally, i don't care about the Bandwagoners - at some stage we have ALL watched something because it was the thing to do, not because we had an interest in it all along.