He is/was a great player that earned himself enough money to live the rest of his life comfortably.
He made a decision to leave for a personal reason, which was reaching for the glory a SB ring brings you. Life is about choices and he chose himself over the organization.
Doesn't look like it's going to work out but because of the second point some do have a right to dislike him.
That said, **** Tony Gonzalez.