It's kind of amazing - friends of mine consider private school (which cost as much as a college education when I was young) to be a must-have. Imagine paying 20-40k a year for your kid's high school, or sometimes grade school! And these are very successful people who went to public school themselves. One is a college flunk-out.
My wife and I don't have kids, so I guess I don't get it. I suspect it's not just about education, but also classism, trying to ensure the kids end up in the right socio-economic class when they grow up.