Aside from the annual "play/retire" drama that gets played out in public rather than privately, it seems like Favre has another motive. If he wants to play the game and/or make millions, great; all the power to him. But instead it appears that he's become obsessed with getting even with Ted Thompson and exacting revenge against the Packers for having the audacity to decide it was time to move on.
From the day Green Bay decided that they needed to go with a new QB, the only team Favre has wanted to play for is the Vikings. In my opinion that tells me his motivation is not love of the game or money; it's a personal vendetta. To me that is what I find very unsettling in this whole matter.
This isn't about Brett Favre's love of the game or wanting to win; it's about him trying to make Thompson look bad with no regards to the fans who cheered him on and made him rich and famous. It's as if he wants to figuratively spit and stomp on the Packers logo for his own self-satisfaction. It just seems very selfish and petty to me.