The fact of the matter is that the implicit assumption of many pro-homeschoolers is that most professional educators - either for individual or systemic reasons - are also not good educators, and would rather take their chances. I can't entirely blame them.
But even if none of those things is true, I keep hearing about classroom size as one of the key determinants of educational outcomes. Well, what's the classroom size for a homeschool? It's however many kids you have. Let's use the standard family size, 2.3 kids. The average school classroom size is around 20 in the US. Well, how much does 2.3 vs. 20 make up for the parent not being a great educator? And what if the person with 20 isn't a great educator either?
It seems like it should be a close call for the vast majority of parents, so at the very least, the question of whether to homeschool should hinge on other considerations.
Most teachers aren’t great educators either, speaking as someone who did it for five years. Homeschooling parents have fewer students and care much, much more about them.