PBA, at the time that R’ Yaakov made his observation kids actually did kid things and were predictable. Today’s generation of kids are not the same as back then. Mothers are NOT at home raising them, teaching and guiding them. The leniency as well as the problems that kids have to know were not part and parcel of the problems and issues that R’ Yakov and his constituents were faced with.
I am quite sure that no one asked R’ Yaakov whether his child should take medication for ADD or ADHD at the time, nor were there so many sheilos about the shiksas in the home or all the therapies that a child needs. Parents had different roles then, they were more present in their kids lives and they were more a part of their everyday interactions.
So no I don’t disagree with R’ Yaakov, it was an appropriate observation at the time.