All this says to me is that YC does not directly fund Googles and Facebooks. This is still very good for the founders. They can take their exit money and self-fund whatever they want.
Google and Facebook are two companies out of many thousands (if not millions) of startups. The odds of anybody that big coming out of anywhere are microscopic. That being said, Dropbox and AirBNB are massive and very young companies. Between those two and the 150+ startups funded in the past 18 months, saying there will be no world-changing startups out of YC is premature.
The biggest companies in the YC portfolio are independent and getting bigger all the time. It still remains to be seen whether a Facebook or Google will come out of YC.
