That's no distinction at all, what people engage with is just one effective way of measuring what people want to see. HN simply optimizes for something else, th

That's no distinction at all, what people engage with is just one effective way of measuring what people want to see. HN simply optimizes for something else, that's no less of a social conditioning tool than optimizing for engagement, just in a different direction. You could say that it's designed from the ground up to show people content that stirs their curiosity enough to comment cautiously, or to hide content that stirs their emotions enough to engage strongly.