Ok, so what do we have on our hands here. A coach that finished 1st, 2nd and 3rd with Milan before the tumultuous disaster-season with them (his final season). Can he be blamed for their decline? Probably in part, but I refuse to believe that it was all down to him. Berlu and Galliani made some terrible decisions in how they handled the situation with the "senators", as well as selling their biggest star players (Ibra and T. Silva). After that, Galliani also failed to strengthen the Milan squad, signing mostly rubbish players.
Allegri has won Serie-A very recently, and that counts for something.
I do believe he made some mistakes during his time at Milan, but I'm confident that he's intelligent enough to know what they were and that he will have learned from them. He's still the same coach who won the Serie-A in 2011, the only difference now being that he has way more experience. If he has learned from his mistakes, then he will be a better coach now than what he was in 2011 when he won the league with the D&G circus outfit.
Also, I do believe he feels he has a bone to pick with Milan, who fired him and made him out to be the big scapegoat. I'm sure he has a desire now to make them realize they were wrong about him, and the best way of doing that is by winning silverware with Juventus.
I miss Conte, but Allegri is our manager now, and as of now I'm 100 % behind him. I'll give him a fair chance to prove himself, and await giving him any criticism before any is due.