(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."