> I see that many people are confused [...] by my take that math talent isn't primarily a matter of genes

Speaking only for myself, I'm not confused at all. Rather I vigorously disagree with this statement, and think that stumping for this counterfactual premise leads to cruel behavior towards children (in particular) who plainly do not have what it takes to learn, for example and in particular, algebra.

> In other words: the people who run the mathematical 100m in under a second don't think it's because of their genes.

This is not their subject of expertise, and they are simply wrong. Why? Simpson's Paradox, ironically.