Very true insights.

I love the distinction re circle of control. IME most issues are cross-team, not internal to a team. That means that leaders need to know about and act on those issues.

Teams also often fail to act on the retro items - again a lack of actual leadership. In Peter Drucker's words, one is missing "a person of action" -- someone who follows up and nudges things forward.

I think a core issue also is the fact that a retro is scheduled. People think of improvements throughout the week; by the time the retro arrives, they have forgot their ideas. But if there is a culture that encourages and expects people to stop working and say "Hey what if we did things this way instead?" - then people would be inspired. Indeed, if we look at truly agile companies, they behave like that: they rely on individuals acting spontaneously, rather than a scheduled innovation sessions.