Last years problems were an organizational failure.
Horford can't challenge a guy like Kyrie if the coach and management won't back him up. They clearly allowed him to do what he wanted because they were terrified he would leave. Arguing with the coach on the sideline, ignoring the play-calls, taking shots at teammates through the media, and being an over-all jerk with impunity.
It was the Celtics organization that made it "Kyrie's Team" and they paid the price.
The problem wasn't that they made it "Kyrie's team", which was 100% the right thing to do. The problem was they didn't follow through and stay consistent with that plan. When guys like Brown and Rozier demonstrated they couldn't get in line, and started making problems, Ainge should have shipped them out for guys that would get with the program.
Ainge tried to placate both Kyrie and the younger players, which clearly was the wrong move. He should have done more to placate Kyrie. Instead Kyrie was left with the impression the team wasn't fully committed to him. When you couple that with the shameful way the local media and fans treated him when things got rough, it's no surprise we ended up in the situation we did. The Celtics have no one but themselves to blame for losing Kyrie.
As for Al's leadership, he's simply just a lead by example type. He isn't the type to lead by his words. There's nothing wrong with that and shouldn't be something to condemn Al for.