It really boils down to most people's experience that in most areas - and education is one of those areas - private parties do a much better job than government bureaucracies. Government schools have turned into cesspools both academically and morally (and also politically).
A public school that is 37th in the nation may be relatively good as compared to other government schools, but we know that government schools have a horrendous track record for the last 30 years.
I say this having attended a government school through 8th grade and also for undergrad - but more importantly as the son of a career public school teacher and a public school superintendant. The only way they could do a proper job was to flout the law. Which they did on occasion. But they hated what the state lawmakers and feds had forced their schools to become.
In a private or homeschool setting there is no need to constantly fight the enemy (of course that depends on the school or the parents). For those who can, either of those options is usually better than a government school.