My 2 cents: He is correct that YCombinator is running little risk doing what it does at this point. That seems pretty obvious now - though it was not when they started. Accelerators were a novelty back then, and YC could have fallen flat on its face.

YCombinator is a pretty low risk deal for entrepreneurs too, come to think of it. Perhaps the author misses this point. If your startup does fail and/or you get tired of the startup game, there's probably a large number of companies willing to take you on as an employee, given the skillset you likely had to get into YC.