I come from a different country and having had a different life experience I have developed a slightly controversial view on the subject.
I believe that in a lot of affluent countries, parents do not feel the intrinsic need to push their children for survival. They know they can provide for their children (either through the state or through their own wealth, etc) and therefore they feel the most important thing for the children is to be happy.
My mum had illiterate parents who had emigrated to the city for work and they pushed the children hard because they wanted a better future for them. Children used to walk to school with no shoes and no food, often inadequate clothes. They didn't have books in the home or a space to sit and do their homework in silence or even any tutors or other help.
Schools were more geared to this culture and teachers with huge classes via a "traditional" setting were able to turn these children (not all of them of course but very many) around via the education system and the support of the parents. By support of the parents I don't mean parents spending hours on their homework as they could not read or write and were too busy working, but supporting the school via ensuring their children took it seriously.
I know it is only anecotdal in a sense, but I know in my mum's generation so many children in her school ended up becoming doctors, lawyers, and other professions from a family that could not read and write or feed them properly.
I think we have a double phenomenon in our society; families are overprotective and schools are too. Children from all backgrounds are not expected to exert themselves in any way and too much importance is placed on "play". I know it's a controversial view, but I really do believe in it.
Then suddenly when the children are older we expect them to change into responsible hard working adults and it becomes a shock to see that this is often very difficult to encourage/enforce, when they have been used to a life of play.
I do not feel we have a successful system right now - I am not saying going back in time is useful as times have moved on but I would definitely be pro a system where we place more expectations and rigour on children from a younger age.