I generally agree in that I don't see them as particularly brilliant, though I think the average is higher and there is a much higher minimum in some capabilities.

And corruption of power is the cause, I suspect. It has poisoned human minds in all places and times; none of us are immune (which is why we design governments that limit individual power). An early lesson in being in charge was that, having nobody to whom I reported, who would see my work and compel me to a high standard, I let things slip.

Reportees rarely help you: Often they don't know what you do; when they do see it, they assume it's acceptable - you know what you want, and you set the standard of quality and establish the norms. Generally they have obvious disincentives against disapproving of you, and not just as some political tactic but for personal comfort: days are much more pleasant if your boss is friendly. They will give positive or at least non-negative responses to most substandard boss work.

I had to learn to think of it in two ways: First, would I accept this work from someone reporting to me? Second, I internalized the medium- and long-term consequences of substandard leadership and management: once your organization has caught that disease, once that's your reputation, it's very hard to change.