Imagine if HN had an army of animatronic robots run an arm-wrestling tournament every hour to determine which stories reach the front page. That would also be an impressive feat of engineering, but it wouldn't tell us anything about which stories deserve to be on the front page due to their inherent value, so it'd be a huge waste of resources, and make HN worse for readers.

HFTs are not publishing a lot of useful results in AI or game theory. They are in a zero-sum game against each other as well as all legitimate investors, and all their profits come at the expense of people trying to better route society's resources.

I'm not sure I understand what you are saying. Would you elaborate?