I disagree heavily with your argument. If the student is struggling with fractions and long division, I don't think you can blame schools "pandering to the slowest student" for such a problem. If they are struggling so much with basic concepts, I'd have to argue that they are the slow students.

> We don't see these results in adults in other countries because they don't burn out their students at such an early age.

If you've looked at education in other countries, I don't understand how you can say this. Many places push their students far harder than the US (for example, Singapore, Japan, South Korea). Rote memorization is pushed far harder as well. How is the material that is taught any less "useless" in the eyes of students in these countries?

I think culture definitely comes into play here. I'm not going to say incompetent teachers don't exist or that there isn't too much bureaucracy in schools; there clearly is, however, laying the blame entirely at their feet is being dishonest. I think culture and parental expectations play a larger part than many people want to admit.