YC never said they would fund no-idea founders. They said they would let them apply. It's an experiment. Maybe they'll fund them; maybe they won't. This is only the first step. When you consider how much experience and data YC has now, you should assume they'll use that wealth of information to determine if a no-idea set of founders matches the qualities they attribute to success in previous start-ups. They'll probably also talk to them about different types of ideas and projects in the actual interview.
People shitting on this idea appear to be assuming that YC is run by a bunch of idiots.