I think he undercuts his own argument. If the idea only takes four hours to build, and the result is a commercially value product, then how can he argue the idea isn't the uniquely valuable component, and his labor is really the commodity? Does he really believe that _nobody_else_ can build it in 4 hours or so? Obviously, execution is important. But if someone has an idea that's great and doesn't require a lot of exe…
The main differentiators in consumer web startups tend to be: the speed and creativity with which the team can iterate, the quality of the user experience and design, and, if all goes well, the ability of the architecture to scale. The capacity to do these 3 things well is relatively rare. Finding a person or a team with these skills is exceedingly difficult (especially in this talent market).
So yeah, I do stand by my assertion that the starting-point idea is the commodity, and the ability to build and design a decently scalable web-app in 4 hours (and then get user feedback and push another version later that same day) is a rare skill---especially on the open market, since most such individuals are either well-employed at companies or working on their own.