Blaming Kane for a team not defending is a coaching issue. He's bad defensively. Pretty much always has been. You take the game breaking offensive talent every day of the week.
True. There is merit to the argument that Kane doesnt drive or control 5v5 play, and therefore needs particular deployment to come out better-than-even in his ice-time. But that’s been true his entire career. He’ll always beat out his own xGF, but the team with him on the ice doesn't necessarily.
Anybody signing Kane should have known going in that they were adding a glass cannon to their arsenal.
That said it’s ironic if coaching turns out to be an issue as far as leveraging Kane effectively within the system, cause it was widely reported that the coach was a huge reason Kane chose Detroit.