I suspect this stems from some kind of ego factor in that when others succeed one wants it to be due to luck and not some factor that makes the other person "better" than they are, and that when others fail one wants it to be due to the other person being "worse" than they are.
Edit: I must admit that I've seen more and more of this on HN as its audience grows and changes, which is rather unfortunate. :(
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.