It is true that kids learn social skills much more effectively and naturally as active members of a larger cluster of their peers. I think there is plenty of hard evidence for that. In industrialized societies there is another level or organization (network or networks is more complex) than per-industraliazed one. No argument or proposal is made in the article of how to organize and naturally allow kids to be with other kids in such environment (which has a more rapid pace of living with higher social pressures).