how rep can be gamed in this use case

What's there to explain? You are well aware that phishing is related to hacking, 70+ reputation 4+ accounts are spamming liquidity is low on hive. They r more likely hacked. You have seen dapps losing all their user keys in one attack. Thousands of accounts gone to hackers. I won't name a dapp as I am adviced to not mention the specific incident.

Where ever you look, rep system of 250+ is broken because I can imagine the accounts who have 70+ reputation and are anti hive. Once they decline rewards, it can't be reduced further so we would be stuck with bad actors.

you lack factual basis for this insistence on stake instead of rep. Why?

To answer your why, u r known as someone who rarely sees other person's perspective of the world. Before u jumped in this comment section, your reputation of not able to see other's perspective was here before u.

I am not interested to convince you or put effort to convince you, as I already reached a conclusion that it's waste of my energy and efforts.

Sorry, it u don't like what I wrote but I hope it answers your why.