The point of this approach to education isn't to say that teachers are unnecessary or that parents possess all of the knowledge that their children will need. It's that children have an innate curiosity that is woefully underutilized by conventional educational systems, which if encouraged can lead to the counter-intuitive result in which children teach themselves or seek out mentors on their own.
In my particular case, we were a weekly fixture at our local small town library, which fed my curiosity about chemistry and to some extent electrical engineering. Thankfully dial-up ISPs started to pop up around the time I was getting seriously into computers, so I was able to download an freeware C compiler and...well I'm posting on HN so it's obvious how that turned out.
Might I have had a similarly inspiring programming teacher at our local public school? I suppose it's possible. Might I have turned out just as intellectually curious and confident after years of public middle and high school? I doubt it but who knows. Was I in any way limited by the bounds of my parents' knowledge or ability to each? Not in the slightest.