A question and an answer can be both upvoted and downvoted. Why by a comment can you only upvote? What if I think it is wrong, why can I not downvote it?
1 Answer
Firstly, there are obviously others that agree with you (myself excluded). However, the current SO policy delineated over here is that downvotes for comments will not be allowed/implemented.
The basic thought is that if you disagree with a comment, you should post a follow-up comment that says so (and thereby explains your disagreement). On the other hand, if you agree with a comment, we really don't want you leaving a comment saying "+1," "me too" or the like, so we let you upvote it.
status-declined
because of those discussions (one of which asks the same question and was so tagged by Jeff Atwood).