In other words: you are welcome to spend unlimited hours and dollars finding and exploiting the flaws in HN's ranking model simply to prove a point, but hopefully, you have better things to do. Similarly, the HN team has better things to do than investing resources to defeat the (unlikely) adversaries who harness both skill and irrationality.

(This wrinkle of Kerckhoff's Principle comes up a lot in systems security work, which is why I was moved to comment about it.)

And it's usually a sign that the one trying to shut down a discussion with this argument is wrong. :-)

Usual forum scenario: changing your SSH port to a non-standard port is security by obscurity and doesn't do anything. Usual reply: it doesn't cost me anything (except a few minutes of my time), but may keep a non-sophisticated attacker out – think some automated script kiddie software.

You mentioned that you're working on an HN clone. Perhaps you'll figure this out.