I dont think its all Allegri´s fault. Part of it, not all.
Firstly, its palpable that we play better with the new formation, but like i pointed days ago before this game...we would risk fatigue because lack of players to rotate, and it seems it has started to affect us, wit this udinese game.
Now we are in a crossroad, because we need to rotate the personel but this would require a change in formation to a variation of 3 center midfielders because thats how we play. The thing is that our 3 CM variants didnt work before. Maybe it can be different now that we have Rincon to put the workload as a B2B. But well..
About Allegri, IMO something broke after the supercoppa MIlan game, i think he will leave.