Indeed, I was thinking where are these rational managers where you can discuss things openly. It seems the world of management is full of petty narcissistic control freaks.
It can sure seem that way -- and no doubt is that way, in certain situations.
More often I find they're simply ... scared. Of how they'll be evaluated, or what will happen if they make a mistake (or heavens, let someone below them make a mistake). Or of simply being "found out" (that they're not nearly as experienced or as sage in their advice as others have made them out to be).
These managers definitely do exist - I have had them, I have seen them, and I have tried to be one.
Perhaps I should have included "rational conversation is possible" as a decision point in the flowchart, with a negative answer leading to "you should leave anyway"!
I could work for a boss that I couldn't trust with that data, but I much prefer working for one that I can and I try to be the one that my directs can trust with it.