Err...well, the first point in that presentation claims that "everyone can learn math to the highest levels." I find that statement offensive. Everyone most certainly cannot learn complex analysis, tensor calculus, or, even harder (!) dream up new methods for integrating complex mathematical expressions and then prove them rigorously. Claiming that anyone can do this is wishful thinking at best and can be harmful. The presentation also claims that being born with a "math brain" is a "damaging myth," which is insulting to people who clearly have talent for mathematics.
The article seems to be aimed at high school and middle school teachers, so I think mentally, I took that sentence to mean "everyone can learn math to the highest levels (taught in high schools)." I think that modified like that, it actually is true, or close enough to true. Even people with limited talent for mathematics can probably be taught basic calculus, given enough time and the right methods. I don't think you need a "math brain" to learn those topics. You don't need a "writing brain" to be able to learn honors English in high school, either, though few students have (or need) what it takes to become professional writers, or even to succeed as college English majors.
I have trouble understanding why Americans are so loathe to face the reality that some people are just smarter than others.
This statement seems to me to be just as offensive as the one you took offense to. There's no need to characterize a particular area of muddy thinking as uniquely American. Plenty of Americans disagree (including you, going by your location), and plenty of non-Americans would go along with it.
