We aren't spending the money on the parents though, we are spending it on their children, who deserve that attempt even if they aren't able to fully take advant

We aren't spending the money on the parents though, we are spending it on their children, who deserve that attempt even if they aren't able to fully take advantage of it. Ruthlessly optimizing use of "the public's money" is not inherently virtuous, but providing the universal opportunity for education is. If it is spent to offer an education, and that offer is not accepted, it is still money well spent.