I personally could not let myself root for a team other than my hometown team. Whats the joy in being a fan of an out of town team when there is no one to share your excitement with? Not everyone is lucky to be born and raised with a local sports team, but when you are, its a no brainer to root for your home team, even if they suck. I have never lived anywhere other than Miami, so maybe my opinion will change if I have to live in a new city long term and support that team, but nothing compares to your real home town.
Also, I am so used to being a fan of a bad franchise that I can't help but think the time is coming. I have been on this Earth for almost 23 years now, the chances of us getting that good mojo at some point in my life should be pretty high. We can't possibly suck for my entire life time.