One of the shocking lessons first time managers often learn is that they have far, far less power than they perceived managers to have. Unfortunately, learning this makes them more likely to dismiss non-manager concerns about the distorting impact that the presence of a manager has on conversation (Because THEY aren't pointy haired, right?)
@rdonoghue Holds for a lot of old school micromanaging managers too, though perhaps rooted in a different cause. My old boss was good guy, good at fighting organizational battles for the team, but as scrum was introduced he did not trust us to self organize.