From this page, I can see that a lot of the moderators of previous years still currently have the moderator privilege, I'm not saying this is a bad thing, but it's kind of counter-intuitive to me since it doesn't look like how moderators work in other environments.
So here are my questions:
Is it true that moderators are able to keep their privileges until they willingly resign, even after the year they were elected?
If so, what's the reason behind this? The more the better(of course quality matters, this goes without saying)?