I have a feeling a really large percentage of homeschooling is about religious separatism and political separatism, and not about academic performance. Yes, you'll hear HN commenters sing the praises of homeschooling because this site is going to be disproportionately represented by the group doing it for actual educational reasons.

Also, we HN commenters typically see the success stories around us at work, not the failure stories. We all know that guy on the QA team who's a genius and credits his success to homeschooling, but we don't know the countless numbers of grown adults who are trapped as housewives who can't get a job because they never learned 5th grade multiplication.

That may be so, especially if you add a sort of "cultural separatism" (a la the hippies I mentioned). An odd thing I see recently too is people who seem to believe they're making various choices for educational reasons, but it's not clear if the education they're moving to is any better. They just do it because they perceive their child as being unhappy or stifled somehow. There seem to be, for instance, more and more parents who believe their kid is unusually smart and should be on some kind of fast track or not have to do certain things, even when there's little objective evidence of the kid's abilities.

Both were certainly major motivating factors for my parents’ choice to homeschool me in the 90s. Quality of education was a concern too, but it very much took a back seat to the other two.

The overwhelming majority of other homeschooling parents they had contact with also held separatist motivations.