If the team is blowing double digit leads in the 4th quarter that isnt the coach's fault man. That's the players being mentally soft. I'm sorry Quin couldnt coach the ability to care about defense or ball movement into Donovan Mitchell.
The culture of the team and accountability of the players is also the coach's responsibility.
I'm not gonna sit here and say that Quin simply is a terrible coach, but he did a bad job the last two years. I get that he has to work with human beings and not some simple command-and-control apparatus like in a video game, but it doesn't change the fact that the team executing is his responsibility. Mitchell was a little **** that ****ed up a lot of the cultural components, but again, it's Quin's job to deal with that. I'm not saying that is easy.
Quin deserved to be fired and I think there's reason to believe that that is more what happened than is being reported. The whole team deserved to be nuked, and the job isn't finished.