While I am a fan of many college sports, I am not especially devoted to any particular team. And when it comes to the professional leagues, I lost interest after my baseball card days in Cincinnati; I'm frankly amazed that anyone is emotionally tied to teams on which many of the players change squads every year.
Though it is politically correct to root for the underdog, unless one's alma mater or home team is favored, I generally prefer to see the best team win. Of course, it's more enjoyable to watch a close match than a blowout, but, in the end, I want the better team or individual to prevail. After all, underdog victories are generally due to a poor performance by the favored contestant.
My inclination to root for the champion is surely tied to my naturalist philosophy. In nature, the best equipped species or pack member is the victor (unless luck intervenes) and those of us who are students of nature admire traits that favor victory and survival. Nature is not sentimental; she has no interest in how the game is played and only rewards the winner. In the end, the purpose of life is to protect and pass along our genes; second place is often fatal and extinction is not an option.