Additionally, I don't think anyone was criticizing the book on the basis that working kids like slaves doesn't produce academic results, just that doing so may be harmful and unethical. Even Mussolini got the trains running on time.
Thanks, I guess I never looked beyond the claims of the high-school survey of European history. There are still, no doubt, plenty of examples of people achieving certain results at the expense of more important ones (treating people like people, for instance).