I'm a Yankee fan but I'm not from New York. I was born in NJ outside NYC and raised in Florida, but I love the Yankees because my whole family loves the Yankees and all my relatives are in the New York area and I been watching the Yankees with my dad since I was too young to even have an opinion on baseball. My other 3 favorite sports teams are the NY Rangers, Knicks, and Giants. So 3 out of 4 of my favorite teams embarrassed themselves last year, I think its safe to say I don't only like my teams when they win. Even though they totally sucked I went to see the Rangers in Miami last year, same with the Knicks, and this season I went to two Yankees games in Tampa.
I don't think it should matter where your from when it comes to what team you like. I think as long as you stick with that team no matter what, and follow them closer than just finding out the scores after the games. Hell, whos to say the most rabid Miami Dolphin fan in the world can't live in Seattle?