We've been slowly backing away from using Community Wiki in most situations. That doesn't mean the badge is a bad idea. Rather, we'd want to find a way to make a badge that encourages the rather nuanced behavior we want to endorse. And that's not going to be easy. If you have some ideas about how to make a badge that does something other than cause people to ...
If you post all of the ones that need an explanation, I will expand this answer.
That description you posted means that your answers that were accepted yet have a zero score (no votes, or upvotes and downvotes cancel out) represent 20% of your total answers. There must be more than 5 of these to get the badge.
Does that make sense?