> don't know why you think stupidity is an advantage in a dangerous or difficult situation

Not stupidity. Docileness. Staying low and being scared versus wandering out because something caught your interest.

> you don't have to do anything to a smart kid in order to graduate a smart kid

What are you basing this on? The evidence from gifted programs suggests the opposite–under-stimulated smart kids can become problem kids fast.

> give full scholarships to really talented kids (who have already proved their superiority in often very adverse circumstances), and charge the sky to the idiot children of the upper middle class

What are you basing this on? Most elite schools charge nothing to families making less than the median household wage.