I can think of a few reasons why we shouldn't optimize purely for the academic achievements of our most talented students: -Less excellent students tend to benefit from having more excellent students in their classes -Even if their academic outlooks are improved, the excellent students are segregated from having to learn how to deal with a wide range of intellectual levels and abilities -I'm not convinced it's really the most efficient way to allocate our educational resources, especially as there's pretty clear evidence that "excellence" in students is correlated to affluence, so we might really just be segregating by class anyway.