I don't see it that way. They made it a game away from the finals without Kyrie so it's on him to harness that energy and lead them right. He didn't. Instead he hemmed and hawed over even being there at all. It ended up a lost season because the youngins and Horford easily make the second round minimum and would have more experience.
The season became about Kyrie instead of their development. That's a tough pill for Rozier, Brown, Tatum
Yes and no. I definitely agree that Kyrie didn't step up and lead and that much of the failure falls on him. He was the superstar player and it's up to him to pull everyone together.
However, plenty of the blame goes to the Celtics kids as well. In order to lead a group, the group must be willing to follow.
Early in the season, when Kyrie talked about apologizing to Lebron re: not accepting/understanding his leadership...most focused on whether or not that meant Kyrie wanted to play with Lebron again and/or the optics of speaking out about his teammates like that and the timing of it all.
I don't remember anyone mentioning that maybe Kyrie had a point and that last seasons success had the Celtics kids feeling a little full of themselves and maybe they weren't as open to Kyrie's leadership as they should/could have been.
I think Kyrie deserves plenty of blame, but the kids aren't blameless either.