Q: Why are classification systems not based on physical appearance?

A: Due to massive protests and years of costly litigations.

It seems that parents are much more comfortable with the current education model, where the lives of their children are determined based on a series of arbitrary "grades" determined by random tests administered by complete strangers, than a more realistic model, where the students deemed most sexually desirable by their peers get the most opportunities to advance.

Thank God we still have the entertainment industry.