>"but could Airbnb have been as successful had they not joined YC?"

These guys had a good idea, some luck, and were able to execute. I doubt that the "brand" of their money or broad aphorisms from VCs had much to do with any of it.

For all intents and purposes, money is money. There's an element of "tech celebrity" in the Valley, and big-name VCs are part of that. In reality, successful businesses around the country are built, every day, by hard-working entrepreneurs who bootstrap it (because their business is making money) or get funding my more traditional means. I don't think VCs have any "secret sauce" for success.