I play/host mafia over on another forum (not CARA, in case people wonder) where most people frequently come off as totally apathetic toward actually playing the game, though I've never actually been aware of why (perhaps it's just laziness, though the biggest problem seems to often be nobody is posting = everyone else doesn't feel like posting or being pro-active for whatever reason).
From my modding experience over there, the best way to get everybody's ass into gear is commiting to a "no posts for 24 hours = prod, no posts for 24 hours after prod = modkill" rule and actively enforcing it. 24 hour night phases are also a better way to keep up interest, since a longer break between actual days leads to more apathy when they happen. Of course, I usually host with 72 hour days instead of 48, so. I still basically end up having to rage-rant about people for not committing to the game they signed up for at least once per game (even when I'm playing instead of hosting), but they've been making progress, at least. <_<
It helps if the bar for content is set higher than posting one-liners / sheeping instead of actually talking about why you have the opinions you have, which I guess seems to be a slight problem here from what I've seen, but there's not much you can do about that.
It should be noted that everything in this post is strictly for NOC, since I suck at OC. So... yeah.