Would a time-delayed showing of the comments help?
That said, it seems to me that sites like HN vastly over-reward early posters to popular threads. On the other hand, this is only a bug in so far that it leads to problematic behavior. I don't see people taking advantage of it (yet). I'm more concerned with the problem of under-rewarding late, thoughtful replies. I think this is a critical problem with the Stack Exchange (StackOverflow) platform.
My thinking on late (and hence low-exposure) contributions is more along the lines of weighting. If 10 people read a comment and 5 upvote it, it should be rewarded similarly to a comment with 100 reads and 50 upvotes.