Juric was sacked by La Dea on Tuesday and replaced by Rafaelle Palladino.
Mutti told TMW: "Honestly, after his excellent performance in Marseille, I was convinced that Juric had taken control of Atalanta's situation in terms of character, as well as cohesion and mentality.
"The games against Udinese and Sassuolo were decisive, where we saw a lost and in some ways unexpected Atalanta. The Sassuolo game was the turning point of the season, and the club made this decision.
"It's disappointing to see these changes because Juric worked with great determination, but for the owners it was an inevitable and difficult decision."
On Palladino, he said: "Raffaele is young but experienced. He did very well both at Monza and Florence: I was actually surprised he left Florence after they finished sixth. It's a fitting and fair fit: Palladino is full of ideas and brings enthusiasm, and managing the entire team will be crucial to getting back on track."