I see three reasons.

1. In the US, no child can be left behind. The only way to do it is to lower the plank for everyone.

2. Over-reliance on standardized testing, judging students and teachers by scores alone. Knowing how and when to intelligently guess on multiple choice questions is rewarded, while ability to communicate well during oral exam is not.

3. Textbooks are ridiculous. Lots of paper, with very little density, and crazy expensive. Textbooks in Russia are more like AoPS books.