Why should a fan have to support what the team does if they disagree? That makes no sense.
Because a fan cheers for their team.
I promise you I was not happy to hear that the Lions hired Caldwell, but now that he's hired, I'm hoping the best for him. He's the Lions head coach now. Are you planning on continually complaining as long as Caldwell is coach? Because you're going to have a pretty miserable life for the next few years if that's what you're planning on.