Why has the meaning of community-wiki shifted towards "a way to stop your post being closed" from the original intent of allowing almost anyone to edit the question and provide answers so that the question itself becomes a reference document for the topic under discussion?
Just intrigued and making the question community wiki! (-
If you read many posting here on meta, you will get a consistent message. The purpose of community wiki is to allow collaborative creation of real answers to real questions.
When I look at the questions that end up community wiki, that is not what I see. What I see is that it is used to establish a gray zone between concrete questions with concrete answers (on the one hand) and opinion/discussion on the other. By and large, opinion/discussion gets closed as 'not a real question' or 'subjective and argumentative.' But some number of posts that are not concrete questions with specific answers are allowed to remain -- so long as they are cwiki. The justification for this seems to be 'well, this tripe is too tasty to discard, but no one should get any rep for it.'
I can't think of a single occasion on which I've seen a cwiki question or answer serving as a vehicle for collaboration, or allowing low-rep users to stick an editorial oar into the river of text.
People aren't editing the question or collaboratively editing a single answer to reach a high polish. They are all posting different answers. Dozens of answers. Hundreds of answers. TL;DR No one is going to read all that stuff.
Maybe this is a good thing, and maybe not. It certainly leads to some level of confusion and whining about unequal treatment. (See recent meta question about career questions, e.g.)
I end up thinking that what we need here is to get our story straight. Given the recent ex cathedra pronouncement about leaving some humor questions open, wouldn't it be less stressful to write up and stick to a policy that covers this stuff, instead of having a policy that talks about one phenomenon and a practice that does something else?