Something like that isn't something I'm willing to spend a ton of development time/effort on. So the underlying functionality would have to come from the XenForo developers before it could even be considered.
They already have options that very closely mimic dislikes, they can: (1)Delete your post. (2)Delete your thread. (3)Lock your thread. (4)Ban you. (5)They can criticize you and you dare not respond.(well you can if you're stupid enough to try it)
These are punched authority means, but I means other than these adoption they should simply mark Dislike any abuse post/thread to alert others.
Providing DISLIKE function is not a healthy means of scrutinizing the forum content or members. Because only people when they likes someones post , they like it , its not a good choice to get dislike-d by someone who is no means a contributor to that post. Also there is already a function like WARNING & BANNING is there here in DP , which does similar to what this proposed DISLIKE button would do. (It warns the member of their posting & doesn't ban the post)
In the old system we had pos and neg rep. You could leave a neg rep on any comment you didn't like, or a pos on ones you did like. I'm surprised, I haven't seen anyone mention it. That was sort of a "dislike" button. People could read all their negative feedback, and if it was excessive, it would prevent them from posting in certain areas. With the new system, I thought the like button was the same as giving a pos rep and that we just eliminated the neg rep. I can see the usefulness of the like button. Sometimes you just want to say "I agree" or "Thank you." But I don't see much point in having a dislike button. If you dislike something just explain why you feel that way or ignore it. Plus, some people used to get out of hand with the neg rep, maybe because it's anonymous. Personally, I don't really want a dislike button to use on others comments.
True , DISLIKE without justification will lead to chaos & will become hectic for the staff & moderators in responding to member's requests. LIKE is more than enough , because if you don't like simply leave it & only when you like you are doing to LIKE his post.
@digitalpoint have you looked at this option? http://xenforo.com/community/resources/post-ratings-taking-likes-to-the-next-level.410/ I've used it myself and AVForums.com is using it with a fair amount of success. Might be worth looking into. Personally, having the ability to like something but not dislike is counter intuitive to me. If you recognise the people for doing the good posts, you should recognise those for spamming and contributing nothing to the site. The problem is, policing it, as you know it will be abused!