I really like Allegri tbh. I remember watching his declining Milan teams fare very well against Barcelona. The man knows how to compete in Europe. Its hard to criticize him for what happened in Milan. His team in a span of a year or two lost Ibra, T.Silva, all their veterans who kept the winning culture there (Van Bommel, Ambrosini, Gattuso, Zambrotta, Seedorf, Nesta, Boateng), and other talent (Pato, Cassano).
He managed to get a third place finish, aided by the acquisition of Balotelli at the expense of a budding Stephan El Shaarawy who had carried the team through the first half of the year. The following year, Balotelli's true colours came out, El Shaarawy got hurt, Kaka was cacca, and Robinho just sat there with a shit-eating grin on his face collecting his wages.
For a coach, that's got to feel like his team just got hit by a hurricane.