It is debatable, but I am personally fine without a dislike button. If you feel that there is a poster that is mistaken, you can either reply, ignore, report, or put that user on the ignore list. I in general don't see much benefit for a dislike button in a well moderated community =/.
In order for that to work, you'd need reputation currency. Every like you've received gives you the ability to dislike once or something. That would at least make people think about how to spend them instead of just spamming nerf threads on their stuff. The above is the 1% The 99% is that we just don't need a dislike.
