Why should prestige matter?
Too many Corporate Ladder Climbers have used YC as a resume point to get that next promotion at a corporation b/c they view it as more prestigious than things like a graduate degree.
That's not a positive for YC, it's a negative. Corporate Ladder Climbers block out those that actually want to do a startup.
As long as the quality of the program remains high, and that is entirely dependent on the quality of the partners, then the program can scale.