Ok, so when are fans allowed to be upset? Spring Training? Start of the season? Or do we need to lose 90-100 games again?
There are probably different points to be made about things. I would say you can be mad about Hudson not signing when he actually doesn't sign. Right now it is just a rumour that he is signing with the Twins. When pen is to paper then people can be mad about that and that goes for all free agent signings.
You can be mad about offseason moves that weren't made when spring training begins, and you can clearly and concisely point to which moves were bad and what you would have done differently with full knowledge that if said move works out during the season people retain every right to rub it in your face. The same applies to people that like a move.
When the season actually begins you can be mad whenever you want within reason. I think the angrier people get the funnier it is. How many times have people on this board laughed when we end up winning a game but a strike out in the fourth inning cause a few posters to claim that player was trash and not a real major leaguer and a bum only for said player to end up having a good game and leading to the team winning.