Absolutely not. Truth of the matter is, I despise bandwagon fans. I am a Titans fan, through the good times and the bad. People often ask me how I, being from San Antonio, could like a team from Tennessee. Most of "those" people forget that the Tennessee Titans were once the Houston Oilers, Since theh and the Dallas Cowboys were the only two Texas teams, I went with the Oilers as a kid because I hate the Cowboys.
Bandwagon fans pick a team who is currently winning. They do not bother brushing up on the team's history or that of the sport. A friend of mine is a self=proclaimed Broncos fan, and he began liking the team when they won back to back Super Bowls. I once asked him who the Running Back was (something a regular fan of the NFL should know) and he could not answer. Only one of the greatest backs in NFL history.
So no, I do not believe bandwagon fans to be credible.