I don't want to put too many words in his mouth, but I think the point he's getting at is that there's an opportunity cost to education, above and beyond the (significant) direct costs.

If you spend 4 years studying something, that's four years you can't spend studying something else. If it turns out that you studied the "wrong thing", you are going to be four years behind the people who took the other path. So it's not hard to see how that education program could look like a net negative.