Note: I posted this as a message, but thought it deserved to be a blog.
Bandwagoning is a complicated issue. While a cardinal sin, I think there are situations where the football gods are forgiving. I say that special consideration needs to be given when there are severe front office problems, or when you or a team moves.
-I think there are internal problems with a team, management, or ownership that warrant acceptable Bandwagoning. For example, I could give NY Knicks fans a pass for ditching during the Isiah Thomas era, and then returning when he is gone (but I won't because they are NY fans 
) . I wouldn't crucify Redskin fans for jumping ship due to Dan Snyder; everyone knows his ridiculous FA habits that have been running the team into the ground, but not everyone knows how he literally rapes fans with his outrageous ticket, parking, stadium food and beer prices. I also would give 'skins fans a pass if they came back when Joe Gibbs was hired. At the same time there is a special place in sports heaven, a sainthood if you will, for those that stand by their teams in these dark and desperate times.
-I also give special consideration when someone moves. I think you are allowed to take pride in your home and community to the point where it can transcend sports. A such, I think you get a pass if you move and jump on the home town team's bandwagon. I think if you move to Buffalo you are allowed to become a Bills / Sabres fan (lord knows there isn't anything else to do there 
).
-However I am dubious of the 'Alma Mater' line of Bandwagoning. I don't think you can give special concession just because player X from your U got drafted. Too many players get drafted making it too convenient to jump from team to team. Every Bandwagon jumping scenario I know of (that involved favorite college players going pro) has felt fake twisted and perverted to me. Seriously, who here hasn't heard of at least 1 person who jumped on the Patriots' bandwagon because Tom Brady played at Michigan? And who didn't feel that wasn't a lousy reason to all of a sudden be a patriots fan? This goes for Free Agents as well. I am fine with increased fandom, and owning new jerseys, but I don't feel like you can change your #1 team due to draft or free agent movement.
This brings up a side issue I want to mention. I think you can be a fan of a team and wear jerseys from other teams. I don't think wearing a Jersey constitutes having jumped bandwagons. That doesn't mean there can't be sports apparel douchebaggery. If you ask a friend about their new jersey and it is a lame excuse, have no fear; the retribution of the football gods is coming and it both swift and merciless.
-I think when a team moves to your location, or when an expansion club is created, you are allowed to jump ship. Personally, as a Baltimore Ravens fanatic, who isn't old enough to have been a Baltimore Colts fan, I am a bandwagon jumper in this regards (however for some reason I have inherited a hatred for the Irsay family and the Colts). If you don't give this scenario a pass, you have a whole generation of Ravens fans who would be doomed to Dante's ring of hell reserved for bandwagon jumpers.
I know bandwagon purists will say that no one gets a pass, and I understand their conservative reasoning (they are like the orthodox of the football religion), however I think there needs to be less strict sports docterine on this topic. I think there is some middle ground between the bandwagon idiot and the saint; I am sure the sports gods have some sort of purgatory set up where you are forced to watch nothing but MLS. Ultimately, whenever I read about bandwagons it will have ties to 1991, Tony Kornheiser, and the Washington Redskins (I still get giddy when I hear him use the "B-word" 
).
