This doesn’t really counter what the OP was saying.
Parent’s comment is calling his misleading statement prompt injection but it’s hyperbole at best. What is meant here is that this comment is not actionable in the sense that prompt injection directly controls its output.
In parent’s example no one is taking a HN commenter’s statement with more than a grain of salt whether or not it’s picked up by some low quality news aggregator. It’s an extremely safe bet that no unverified HN comment has resulted in direct action by a military or significantly affected main stream media perceptions.
Most humans - particularly those in positions of power - have levels of evidence, multiple sanity checks and a chain of command before taking action.
Current LLMs have little to none of this and RLHF is clearly not the answer.