I thought I would see more funny replies like the ShittyLifeProTips, but so many subreddits have people replying with legitimate responses.
You can see them all here:
https://www.reddit.com/user/ModCodeofConduct
Let them. When the rush of a gain of perceived power wears off and they realize how much work is involved running a subreddit for literally no compensation, most of the will wander on.
Or accidentally burn it down. Either way, that's a win.