Allegri is only good in the good times? This is a manager who did not lose his cool and control of the situation, when everyone else was losing it, when Juventus started the season badly (you compare how he handled Juve's poor start and how Mourinho handled our poor start to the season. such a massive contrast). They were in 11th after taking only 12 points from their first 10 matches, sitting 11 points then leaders Roma. Fans were questioning him, people thought Juventus were gone for the season etc but 13 consecutive league wins later, they are second in table and sit just 2 points behind Napoli.
If that's not enough for you, Allegri also showed the same attitude with Milan in the 2012/13 season. The club sold Thiago Silva and Ibrahimovic - two of Milan's best players - in the summer of 2012, took only 7 points from their first 8 matches. But despite that, despite having a very average squad at his disposal to work with, he still managed to guide Milan to third place, losing only 3 more times since that eighth game (he lost 5 of the first 8). If anything, Allegri has shown that he has the temperament and know-how of how to navigate a team out of sticky situations.