Somehow I feel Deron Williams was associated with this firing, didn't like the system one bit nor did Gerald Wallace.
I think it more so had to do with the fact Avery lost the lockerroom, and no one was responding to him. Look at the Christmas game, everyone was playing so bored, no heart, no passion. A change was desperately needed. Deron Williams voiced an opinion that a lot of the players had, I don't think it falls solely on the shoulders of him.