I would slightly disagree. I'm a new contributor, here, but I simply look at the comments on my profile and see the scores which helps me determine when I have, perhaps, strayed. It helps me refine what I contribute and how, based on the community response. Of course, I then have to interpret what scores are the result of my contributing something of value versus people simply agreeing with the sentiment of my comment, but that isn't too hard. I don't know that enough people would see public scores and derive what is good or bad before contributing to be a reason for tagging every post with them.

I think the way the system is, now, isn't ideal but it is decent. It eliminates the temptation of a lot of people to post with the intention of getting lots of points so everyone sees how awesome they or their comment are, but still provides the input on those comments for the individual to see. So it helps shape your quality, without making the "ranking" a public competition.

As for curating the live contents of an actual discussion . . . I don't think exact point numbers is necessary for that. If I only want to read the best top half of the comments in a discussion, I don't need to know that a set of comments got 12, 32, 48, and 119 points. I just need them to be displayed in such a way that I can discern the top-most content. Physically weight the comments (in color, boldness, placement, or other possible options) so that the top 20% of comments appear in one way, the next 40% appear another, and the bottom 20-40% appear in yet another way. Easy to visually discern and pick through, but the top comments are then tied to the top comments in relation to that exact discussion and not a hardset number of "anything over 50 points is really great - period". (For all I know, this may be how HN does it - I tend to read most comments already, so I'm not sure).