I'm even more surprised by people who think that parents just don't have the people-skills to teach their kids. My husband and I were discussing it the other day (he's a homeschool grad too; we'll be unleashing a second generation of homeschool misfits one of these years) and realized that professional teachers are so focused on the skills you need to handle a classroom full of discipline problems, or to teach 30 kids at once, that they just don't realize that it's really really easy to teach your own kids one-on-one. There's already a love and respect relationship there, already a teacher mode if the parents are any good at all.
Going from "not schooled" to starting kindergarten at home was, for me, so subtle I don't remember it. One day we were working on ABCs, the next I was doing math pages in an organized fashion.
I agree ... especially when they go on to expect that the same parents who apparently lack the ability to teach their children are going to help the same children with their homework!