They crave the attention that the "lovable loser" tag brings.
Hmmmm..., how does that explain the many long time Red Sox fans who were also Celtics fans back in the 60's, 70's, and 80's when Boston's basketball dynasty went on and on? How does that explain that most Red Sox fans also rooted for the Patriots when they won their SuperBowl a few years back.
How does that explain the tens of thousands of Cubs fans who also rooted for those Chicago Bulls teams and those Chicago Bears teams that won their fair share of championships?
The lovable loser tag is BS. People who live in or grew up near Boston are Red Sox fans, Celtics fans, Bruins fans, and Patriot fans. People who grew up in New York are Mets or Yankees fans. Out here in Northern California people root for the A's or Giants.
But to think logically and critically about these types of things is beyond most people.