I don't disagree with you. But the post I replied to said YC would replace traditional credentialing mechanisms. I don't think it necessarily follows, because YC plays in an industry that didn't care much about traditional credentialing mechanisms to begin with.

Using things like YC for credentialing depends on the relatively unusual characteristic of the internet startup industry that you can do "real work" in the field with no little to no startup capital or association with a big company. For this reason, software companies have always been impressed by project credentials. Aside from a short burst when Google was really focusing on Stanford/Berkeley PhD's, traditional educational credentialing never really took root in the industry. I have a hard time seeing how things like YC will replace traditional credentialing mechanisms in other fields. Is Lockheed-Martin going to look at your jetenginegithub.com account to decide whether to hire you?