Patriots fans in New England are obnoxiously spoiled. I enjoy the silence when they get knocked out. (Beyond the usual blaming that goes on as to why they lost).
I'm 32 years old and have lived in New England my whole life. Prior to 2001 no one up here gave a crap about the Pats outside of 1985 and 1996. There was some mild interest when Bledsoe was drafted but that is about it. Growing up all of my friends were either Cowboys, 49ers or Giants fans. The only ones who rooted for the Pats were the children of true, die hard Pats fans. Few and far in between.
To sum it up, you have no idea how bandwagon and fickle the fans are up here. Once Brady goes and NE experiences a decade like Miami has just endured it will be a joke. And to sum up their football knowledge, many wanted NE to trade Brady when Cassel's contract was up. They go with what is popular and then go away when its over.
I'm sure its like that in any city, but the obnoxious, arrogant and clueless attitude you described is spot on.