The description that I see for the moderator's "convert to wiki" action says:
Community wiki questions don't accrue rep and have a lower full editing reputation threshold. Questions should be manually converted to community wiki when they are marginal fits or 'list of X' questions that contain enough value to avoid deletion. This affects the question and all answers.
Should not the sentence I highlighted be changed?
If I understand well, a question that is a marginal fit should be edited to make it a perfect fit, and list questions that contain enough value to avoid deletion should be locked for historical significance; in neither the cases a question should be made Community Wiki (except, maybe, in very exceptional cases).