Glad you asked. To us in Singapore, the South Koreans and Japanese actually look a tad excessive (what with their headbands and everything in that article). But it's more likely just a function of how they display their emphasis on school testing. We probably care as much about test results, but don't display it in the same way.

Test results matter when a majority of successful people got where they were because of their results. They did well in school and got good jobs (often in foreign MNCs); not many started their own businesses. Add to this the cultural motivation of wanting to keep up with the Joneses (being 'kiasu', in our lingo) and you have a strong incentive for parents to be all "responsible" for their kid by making sure she gets tutoring in whatever subjects she's weak in and she does additional practice outside of homework, often at a harder level than in school.

And of course, in the good schools, the ones that take in a higher-scoring crop of students, the teachers create harder test papers for their students to keep them motivated (we can't have everyone getting As now, can we?), and so parents go to tutoring companies with "challenging" or "enriching" programmes to make sure their kids keep up. The problems at this end of the pool get a bit ridiculous, and people end up complaining: http://everythingalsocomplain.com/2011/09/10/primary-6-maths...

The tide is turning slightly as new parents, freshly emerged from the competitive sea of schooling, take a less intense view of the importance of academic performance, and recognise that there are other paths that their kids can take in life that don't rely on test scores. We've opened specialist schools in arts, music, sports and design in recent years. But there's still a heavy economic pressure to do well and get good jobs in finance, medicine, law and so on, so I don't expect the culture of focus on education will weaken significantly in the near future.

I think the fundamentally different culture of American schools means that many Asian approaches will never transfer well; but there are still improvements that can be made, e.g. in the area of curriculum, in teacher training and ongoing development, etc. American schools are incredibly diverse in populations and practices; they have big weaknesses and big strengths. I think it would be good to have a unified tough-but-capable program for the struggling schools in poorer neighbourhoods, while letting strong/specialised schools do their thing. That would be something like the best of both worlds.