I'm glad someone else noticed this. The whole thing felt really strangely phrased.

It's possible that it was written by committee, (i.e. everyone editing a Google doc), which often leads to this kind of writing.

Alternatively, maybe they just didn't want it to sound too much like PG's writing style.

Still, phrases like "Y Combinator’s goal is to cause there to be more startups, by helping founders to start them." don't exactly flow.