If you want to maximize education per tax dollar then you need to separate out the smart kids into their own schools. Benefits of education are not evenly distributed. It is heavily weighted towards the right tail.
Pretending that the outcome for everyone should be college and a degree is part of the problem - admitting that outcomes may be different allows you to create different paths adjusted for abilities (think trade school instead of high school, etc). Forcing everyone into the same mold results in a broken mold.
