As luckiestman mentioned, the stuff he was doing on D was really bizarre, and went beyond execution. It doesn’t mean that Kyrie Irving was solely responsible for the problems, or that things will be perfect now that he’s gone.This is baseless on both fronts.
The more obvious answer for Irving's performance in the playoffs is pretty simple. He was Boston's only true, consistent scoring threat. He was also Boston's only player who could also consistently generate his own looks. As such, opposing teams schemed to stop him and let the rest of the Celtics beat them, knowing full well that if they were successful, it would take an outlier performance by any of those players to make them pay.
We can debate where Irving ranks versus the different tiers of players but the other teams that went deep in the playoffs had multiple scoring threats without exception. Boston did not. As such, I don't think criticizing him for not carrying a flawed Boston team deeper is entirely fair.
But the dude was doing weird shit, especially for someone with his BBIQ.