We culturally have a problem with the inability to accurately judge, much less even tell parents what their children are capable of, or not capable of.

In the end even with the best education, some people will grow up to be tow truck drivers, low skill factory workers, or service industry personal - its just how the split works out - not everyone is going to be super smart, some will be average, some will be below average, and some will give a wet bucket of sand a run for its money.