My goal in not showing points on comments was to prevent the sort of contentious exchanges where people (in this case literally) try to score points off one another. I feel like it has done that to some extent, but at a cost in other areas. So which do you prefer?
Here's the earlier thread about it: http://news.ycombinator.com/item?id=2403716
Also, I've been planning to write a longer blog post on the following, but given that I've had no time lately and am not likely to have any soon, I'll just float the idea here.
One idea I've had that I think might be interesting is dealing with upvotes or points in terms of logarithmic scales. That is, it takes one upvote/point to get a comment from 1-10, 2 upvotes/point to get from 11-20, etc. (Exact numbers would have to be scaled, of course.) I find that going into a thread an hour or two old and seeing comments with 50-100 points is a major disincentive to commenting, even if I have something to say. That comment or couple of comments and their resulting threads are going to make sure very few people ever read what I've written. An appropriately scaled log-scale system might make it so that really really good comments still get really really high scores, but so that others (which might have simply come too late in the discussion to be competitive on a raw-point scale) still get a chance at being seen.
(One related idea would be to make the point-approximating graphic log-scale even though the points themselves remain the same underneath.)