Cotton Mather wanted to educate the children in his society with the information most useful to the life that he expected the children to lead. Because he is a Puritan it is natural that he teaches his children Puritan values.
Much like Mather's methods, the American education system is designed so that American children can become productive members of American society (the IB program is an exception). However there is a fatal flaw in the system. America is a conglomeration of countless cultures, beliefs and practices and a public school system, cannot and will never be able to educate children for all of these cultures so the system educates for free thinking. But since the system is entirely standardized and mandated for the same guidelines, regardless of area or majority culture, the goal cannot be achieved.