Well, you made it seem like the only justification for maintaining inequality was a myth about equality of opportunity through education.
But inequality doesn't need to be justified; it is the natural state of things, and there never really can be equality of opportunity, either. Inequality in both outcome and opportunity are as natural as sunrise and sunset, or the changing of the seasons.
Your proposition, in fact, has it backwards. It takes enormous effort to try to establish equality- its like trying to keep a garden free of insects. It means constant pruning, maintenance and expense, and even then, some bugs slip through. A better question would be- how do attempts to establish equality show themselves to be worth the expense?
We have examples in places like Baltimore, where per pupil spending is very high, that the expensive pesticide is is not keeping the insects off of the fruit very well at all. Perhaps some fruit is meant to be eaten by pests?