It's a very difficult problem to solve, but to just "not give a hoot" is hard, given the fact that the order of appearance for comments on HN depends so much on karma.
but to just "not give a hoot" is hard
try it! at 1k or so karma you have more or less nothing to lose.
Same with my submissions - I only care about up-votes there because I want more people to see what I have posted and benefit from it.
I think the karma system could work a lot better but it does do what it's intended which is to separate those who are dedicated to the community from those who are just fly-by trolls. I think that was all it was ever intended to do and in that sense it works well enough.
I think it's an important distinction because it reflects on what would happen when it gets "fixed". For example comments by those who just submit stories would be treated no differently than someone who just came on the site today. But I'd argue that someone who has a couple thousand submit points behind them cares quite a bit about the community and if they felt inspired to comment on something after never having commented before I'd consider that comment of the utmost importance.
So while the karma system is flawed it's not broken. It's just the most basic implementation of it's intent which is to reward people who have contributed to the community with status for having done so.
Which is the problem. If you understand what a karma system is than you understand you're doing damage to a person's actual reputation by down voting them. So the obvious conclusion for anyone who understands the concept of karma points is that down voting is an act designed to cause harm to the person not to express disagreement with the idea.
I can't imagine a person who doesn't have at least a subconscious understanding of such an obvious result so I don't think a notice when someone down votes would change anything
Also your math doesn't demonstrate that much: the incentive for trying to be the first is big (25x an insightfull comment) but there aren't that many opportunities, and it establishes competition for a good thing, having fresh news on HN.
You also tell that the referred mechanism would be gamed by people who would post old pg essays. Then again your scenario is wrong. The mechanism can be implemented to work so that the PG essays as not enough for the demand of points. And if you tell me that people would post other things just for points, isn't that the whole point of the voting/karma system?
There are problems, but I think the karma system is not obviously broken. It's true it's hard to create the right incentives to fight those problems. But HN has done it so better than everyone that I'm confident it will get better soon.
On a side note, has anyone ever tought of dynamic partitions of the community to address the problems of exponential grow and dissolution of identity?
I think the problem arises when thoughtful comments, maybe from people playing devil's advocate, are buried at the bottom on the thread or even worse highlighted in light gray. To be honest it probably is the exceptional case, but it's disappointing the times it does happen that those comments miss their opportunity to generate interesting discussion especially when the rest of the thread is, no offense intended, the usual hacker news echo chamber.
My opinions may be unpopular but it is respected.
It's not that quantifying all of these things wouldn't be great, just that you very quickly will end up with a system way too complex to be reasonable.
At that point it becomes a video game, and loses any semblance of meaning anything whatsoever.