Why American students do poorly in math

An interesting perspective from Steven Pinker: "[American] educational establishment is ignorant of evolution. The ascendant philosophy of mathematical education in the United States is constructivism [..]. Children must actively construct mathematical knowledge for themselves in a social enterprise driven by disagreements about the meanings of concepts. [..] Drill and practice, the routes to automaticity, are called "mechanistic" and seen as detrimental to understanding."
Basically, the idea is that our brains are not wired for math the way they are for other, more "natural", ideas. And math is ruthlessly cumulative: it is impossible to do calculus unless algebra is already at a level of reflex. The only (?) way to do well in math then is to practice. (Hm, recalling my middle-school homeworks of 30+ excersises from Skanavi.. brr.) Somehow this looks like a tough sell in American educational system.