Community Wiki allows you to take other people's answers and replace them with (well) another person's answer to 'cheat' the original poster out of votes/badges.
Community Wiki posts in Stack Overflow exist to allow users to edit other's answers more easily -- to encourage participation. I could (with a mere 750 reputation, IIRC) go into any Community Wiki post and edit an existing answer. But what if I wanted to take a user's popular answer to another (very similar) question and just copy/paste that in? I could do that, and according to the 'rules' of CW, it would not be 'bad'.
Where it becomes unfair is now I'm getting rewards for someone else's answer; and they in turn are deprived of those rewards. Those rewards come in page views to their profile (which may lead to upvotes in other questions) and badges. It's that second part that is most important, it's the part that allows the original author to retain some benefit for a answer he made.
Community Wiki should either
- Not give badges (another Meta SO discussion tracks this)
- Editing should be explicitly limited to improving the current answer without taking someone else's answer from another question wholesale. (clearly impossible)
In the answer to this question, I compiled all of the answers in that post into one answer. This one answer became 'the answer', and I received badges for it.
Later on, in this question, we found out that Question #391523 was a duplicate; and was closed ( I don't necessarily agree with it being closed, since that's a nomination for deletion, in your words). My answer still sits there, getting upvotes.
Gatekiller comes into that question, takes my answer, and replaces the accepted answer in his question with my answer.
As it would stand, the author of that answer would potentially receive dozens of upvotes for an answer he never gave, and I would be left out, with my reward mechanism removed.
- Take out the reward for Community Wiki Posts (OR)
- Institute Guidelines for adding/editing CW posts (AND/OR)
- Explain why the current system is broken.
Also, even if you choose not to do any of these things, a discussion on the merit of this issue would be nice.