I will state what I've said before: The US economic system doesn't merely tolerate mediocrity, it insists on it. Genuinely skilled workers with independent minds pose a risk to the system that must be contained by deskilling jobs and making workers as fungible as possible.
Oddly enough, the "workers" who *are* the most interchangeable are corporate CEOs, relentless narcissists who I know from experience are almost completely lacking in their capacity for original thought and who possess so little introspection that they don't even recognize this incapacity -- universally thinking of themselves as bold visionaries when they are actually acting as a herd.
Carl