In summary, the passion and persistence of grit motivates and carries us over rough seas like a well-made surfboard. We can think of an absence of effort like a crack in our surfboard that needs repair.
Instead of an index of how "genetic" an IQ test is, it's more likely that in Western society-- where learning opportunities differ so drastically from each other-- heritability is telling you just how much the test is influenced by culture.
I think it's fair to say that Richwine is making a fraudulent argument that, contrary to his claims of good science, is the product of his own personal and ideological needs rather than of any good data. The interesting question is why he needs to do this.