I don't think we disagree about executives.
A good executive, while not having expert knowledge in every field he supervises, will have a much better idea about what his limitations are, and he won't "simplify" the world and believe that this simplified model is reality .
Instead he'll use a simplified model to make decisions, in full knowledge of the risks that this brings with it. He'll trust good experts around him to tell him when he messes up - but he won't (and can't) expect the experts to be able to produce (nearly) the same rate of average-to-good decisions that he can do.
A good executive will also generally have pretty good emotional intelligence - there's many forms of intelligence and not all are well recognized.
So an executive is in stark contrast to what the general population does when it comes to understanding the world and making decisions.
Also, did you mean to suggest that I insulted someone with my last paragraph? I think it's a factual statement and it's not really shaped (or intended) as an insult.