He didn't fail to consider that, he just didn't consider that, because he had no reason to consider that, just like he didn't consider the orbit of Pluto or the phases of the moon.
If you think he should have considered and controlled for something, say why explicitly.
I assure you, people do. It's certainly not the case for lower-class people who are just scrambling to survive economically, but if you asked around people who are more affluent, they could definitely afford to reduce their workload to better care for their children.
One colleague was arguing that the standard school system was very destructive to children and alternative schools were doing a much better job making them able to think. However, she also said she is sending her children to a standard school because of the cost and complexity. In other conversations, she mentioned that her neighbor complained about the noise of their private pool cleaning system, which is still an ongoing problem, or how going skydiving was a great experience.
There is a lack of self awareness in how "doing like normal people do" is influential to most people. People work for shit they don't need, and don't really think what is going to bring them happiness.
It's so good that we've got people like you to tell parents how they should live, what they should work for, and, most importantly, how to raise their children. But please lead by example.
Survivorship bias occurs when researchers focus on individuals, groups, or cases that have passed some sort of selection process while ignoring those who did not.
The author made the case that history's geniuses practically all had private tutoring and that the lack of private tutoring may explain today's lack of apparent geniuses. What was the selection process that he ignored? And how does the lack of that selection process recognition hurt the author's argument?
If you think he should have considered and controlled for something, say why explicitly.