I've said this in some of the other threads on this topic, but I'll say it again:
The huge (and incorrect) assumption that people are making about upvotes is that everybody reading the comments is stupid. We're not using the upvote count as a 100% perfect indicator of if somebody is correct or not, we're using it as an indicator of how many upvotes the comment has gotten. It's just one of several things that we can use to judge a comment's merit.
This information is useful, and I cannot fathom a benefit to withholding it.
On stackoverflow the criteria for voting are considerably more concrete, yet it's clear that voting there is strongly biased by vote counts. HN might have more rational voters (though look who's saying so), but they're still human, and the fuzzier criteria, shorter active lives of posts, and volume of comments to scan through probably more than make up for this.
(I could've made this same reply to other comments here.)
The huge (and incorrect) assumption that people are making about upvotes is that everybody reading the comments is stupid. We're not using the upvote count as a 100% perfect indicator of if somebody is correct or not, we're using it as an indicator of how many upvotes the comment has gotten. It's just one of several things that we can use to judge a comment's merit.
This information is useful, and I cannot fathom a benefit to withholding it.