The USA education system does allow their top kids fly freely(which is really a small percentage), however the demanding on the average kids are too little, many kids gave up or drop out and could not find a decent job thereafter. No-child-left-behind can only do so much. There is nearly no grit/hard-working attitude in middle/high schools here at USA comparing to China.
Note 1: Not all Chinese students going overseas are top kids these days anymore, in fact most of them are having a rich dad meanwhile they can not stand up the fierce competition in Chinese schools. Note 2: The Chinese education system(in that sense, the India's) produced lot of "good-enough" engineers eager to fill up the H1B quota annually, those USA kids with the same IQ ended up not being a STEM engineer most likely, which is considered too nerdy or more, too hard for them. -- No pain, no gain.