It means everything for YC's model.
YC does not care about the software.
They care about the founders.
YC's model and ecosystem is explicitly designed to be a who's who club of interconnected founders that are very, very encouraged to """rely""" on each other when building their companies.
YC uses a lot of double speak regarding this ecosystem, but if you explained the concept to a layman on the street they'd tell you exactly what this concept is in just a very few, very blunt words.
Elite-class founders and lots of cheap, imported, or "passionate" labor.
Let's get real here folks.