Isn't it the whole thesis of the Outliers book?
I read from it a combination of the two. In a rambling way it said that in order to even be eligible for an "outlier" outcome you needed to have done the 10k+ hours but that doing the 10k+ hours was not enough.
i.e. Skill & work is necessary but not sufficient to end up building an outlier result like Google/Apple/Facebook/Goldman Sachs etc.