Honestly the means are out there for "elite" students to get their way through the system, there are competitive enrollment high schools that have great teacher, just as there are a select few college's that actually have great professors(not just filler professors, but ones that are actually on the forefront of their subject.).
And well for everyone below the "elite" it's kind of just filler, you have to realize you're one of 300 million, individualized special education just isn't practical. And hell for some people all that a "proper" education would do for them is push them a bit farther and let the comprehend differential equations in stead of Business calc or whatever. And it just doesn't matter that much since you can probably find millions of others who can grasp differential equations withing the education system we hav. You could argue they could go farther, with a more specialized education system, but apparently the goal is to push your very best as far as they can go, not push a large amount of mediocre and semi smart people as far as they can go.
If you ever read "Surly you're joking Mr. Feynmen " he kind of talks about how within the physics field which is an insanely small percentage of the population, there's even a smaller group of the truly elite physicists and how they were assembled at los alamos together and what not, and how it's like an insanely small amount of physicists that are actually "progressive" and the rest just kind of filler who can comprehend the subject but for whatever reason can't extend it.