Not only that, there's a variety of mechanisms built in to boost/identify YC users to other YCers to provide mechanisms of boosting their submitted stories. HN in itself is like a giant voter ring in that way.
It's just that if you're in a YC batch or an alum you get posts, especially job posts, boosted.
I wouldn't pay much mind to this talk of mechanisms and gaming systems, sounds like post-hoc reasoning by outsiders.