Absolutely nothing in the article implies that this father is attempting to expose his children to books or other resources (the internet, perhaps?) about math, science, or history.
It looks like there was a misunderstanding here. It's ambiguous from your original post whether you oppose unschooling in general or the specific approach of the author of this article. It's clear now that you meant the latter and as someone who generally supports unschooling, I do see your point. If I had kids to unschool, I would try to encourage them towards more intellectual pursuits. And if they were anything like I was as a kid, they would enthusiastically take part without coercion (unless I required them to conform to a rigid educational program, in which case coercion would be required frequently).
