Also, the concept of manipulation is very insulting to the readership. Maybe it's sometimes warranted, but on HN of all places, I think people can debate, judge, and flag on their own if they think something is being manipulative.
If arguably the smartest tech group on the internet cannot devise a defense, then we're more doomed than I thought. After all, at the opposite end of the spectrum we have "AI" at Google and other companies banning users based on incomprehensible algorithms. Surely there's a path between the extremes.
Consider for a moment how little it would cost to pay people to post on HN. Other HN readers don't even need to see it; it just needs to get indexed by search engines. That adds the weight of HN to the content which it is linking to as far as the search engines are concerned. They probably aren't measuring HN reader votes.
So the question is, should we allow HN to be used as a lever to promote anything that a financially-backed group wants to promote? Or can we devise ways to reduce or eliminate this?
The kind of thought policing you're proposing will never fly here.