I turned all the communities I modded private and "basically" quit but I understand not completely quitting without thinking about it for a long time. I only modded for like 30K redditors but some of the communitites have millions and they got there with the unseen moderation. Mods love their communities and it's really hard to just turn your back on them after you've cultivated real friendships and so much information has been shared. I think it's a little more complicated than, "F reddit, I'm out". They'll get there though, it's just become sooo much harder to actually mod the community you started.