I can't comment on the persuasiveness of their arguments. But in general, if common sense doesn't win someone over, statistics won't either.
Slavery is, at best, a waste of human resources by sheer common sense.
The real shame, and the real root of the problem one might say, is that children's interests in exploration, in creativity for its own sake, are censored at such an early age in many societies by many parents. Death, taxes, and unlearned lessons - these are certainties of our social disease. You're a great educator. I really appreciate your insight. Amazing what might have happened to history if censors were not involved in this particular incident.