i think it's probably due to the fact that you get as much out of YC as you put into it. If you need help they'll give it to you...they have those kinds of connections.
So the only thing it comes down to is money, and it's pointless to complain about that when you just flamed out and the equity is worth 0.
And if you are a success, you attribute a large part of it to the connections you got through YC.
or <tinfoilhat> they are afraid of getting on PGs bad side, and having him email every person in the valley, saying that they shouldn't work with you</tinfoilhat>