<p>I agree with most of what has been said so far. </p>

<p>Disclaimers: I didn't see the original comment or add +1 to it.  My comments can easily be sharper than average here, so I am not posing as a nice guy, but I would never dispute a moderator's judgement on my comments. </p>

<ul>
<li><p>Comments can be sharper than answers, but they must not be offensive. But give and take is needed: comments must be seen in context and be judged knowing that people can disagree in good faith on what is amusing or not and what is fair comment or not. Comments are often the community's way of having fun, with all that is implied. </p></li>
<li><p>Adding +1 on a comment is not, as I understand it, strictly an upvote. It shows approval of some kind but it has no effect on reputation. Some badges may be awarded depending on the scores for comments that someone receives, but that's secondary and trivial here. </p></li>
<li><p>Part of the problem is clearly that without a following comment explaining why a previous comment got your +1, no one can tell exactly why +1 was given. When I get +1s on comments, the reasons seem to vary, including "agree strongly", "interesting point", "helpful reference", "very amusing", "hi Nick!": elaboration is hardly needed. I suspect without any evidence that the most common single reason among those 10 +1s was something like this: Wicked comment, but I found it amusing. </p></li>
<li><p>I have wanted to be able to put -1 on a comment. Clearly I know that I can flag something obnoxious or add my own comments. But reasons can include a thread being already too long or too heated; the comment already being a digression from the question; my wanting to indicate a polite boo as well as a polite cheer backing comments are I think are correct, interesting, or helpful.  Adding +1 to those comments you think are most telling is the best way to add your own minute cheer, but I have wanted -1 too. </p></li>
</ul>
