(a) HN is the front-end and back-end of a bunch of YC business processes.
(b) The voting ring and antispam features rely on obscurity; they are game-able.
The code for older versions of HN is available, but you'd be better off with the code for lobste.rs.
(c) The standard complaints don't matter because they don't impact growth.
There's a message in that.
It is, "Ship."
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.