YC is a coaching environment. Imagine if you took a professional soccer team and removed the coaches for a month. They would start loosing and if they didn't you would find that one of the players had taken on the role of a coach. This is almost certainly what is happening here.
It might be long enough for some, but not the others. Startups need to have majority of things right even before getting into YC and then improve more under YC mentoring.
