The problem with home schooling is that the student is limited to the abilities of the parent(s) providing the instruction.
Not a bad deal at all if the parents are fairly intelligent, but consider... would you just pull any adult off the street and ask them to teach your child, even if there was a fairy tale world where there was zero chance they would abuse that child?
I sure as hell wouldn't, people are idiots.
Then why are you sending your kids to public schools? If you're a university graduate the odds are fairly good that you're more intelligent, and thus more likely to have a better intuitive grasp of how education works for your child and also have a more refined bullshit detector, than your kids teachers, for education majors are usually drawn from the lowest performing tiers on the SAT. Girls who go to university to major in Dance score higher than Education majors. Education majors (1442) are equidistant between construction workers (1274) and Liberal Arts students (1613).
Most reasons WHY Home-Schooled students have better test scores than Public School Students are as irrelevant as they are obvious: Home-schooled students by definition have many environmental advantages over Public School students that the Public School will
never be able to match. Plus the population of home-schooled students is very small (<4% of total US students) and probably very select (their parents likely began home schooling while they were in the womb). These parents did not just appear in 1996 when home-schooling became legal in all 50 states, and since then the concern of parents about public school teaching quality has not increased much more than it was in 1986, 1976, or 1966, etc. What has changed? Internet access to online curriculum, making home-schooled lesson plans and structure much easier to maintain so they can target successful completion of standardized tests.
What is extraordinary is the attention that such a small population draws from both sides of the partisan spectrum:
Educational Conservatives use the success of <4% of total students (see OP) as some sort of evidence that ALL efforts to educate ALL students attending ALL Public Schools are failing. Clearly, this is not the case.
Educational "Liberals" react to the success of <4% of total students learning outside the public school system as some sort of major tragedy threatening ALL Public Schools.
Again this is clearly not the case.
If any group should be very concerned about this growing 4%, it should be
Private Schools. They are the real competitive substitute for home-schooled students. Parents will find that the economic benefit that home-schooling offers may make it a very popular choice. In fact, I foresee a tremendous rise in demand what was once called "governesses" or private tutors, employed in homes not only of the wealthy, but also in the upper-middle, and even middle class to substitute for private schooling.