I haven't played in almost two years. I played one come back character then and before that was probably another eighteen month lay off or so. So in roughly three years, one character, which is probably the last time I'll ever play CF unless something drastic happens and CF becomes a fun game people actually play again.
I would say if you are the kind of person who likes to solo level, practice and explore and occasionally interact with other players CF can still be fun for you. There's also a place for someone who wants to do that and interact heavily with an immortal who matches your times. I find none of this appealing.
There are two factors that keep me off CF:
1. Low numbers. Finding groups is usually doable (or were a couple years ago) and the solo leveling options are adequate - but it's not as fun. The real problem is finding people to kill. The first month or so of a new character works out okay because people are willing to feel you out. But, once you establish yourself the 2-5 people in your range (usually closer to two) will just avoid you at all costs and finding meaningful, fun fights becomes impossible. I typically end up spending an hour or two grabbing preps and special items to fight impossible matchups, thereby creating a ratio of fun; work of like 5:120 minutes. It's just...boring.
2. The low numbers contain a high percentage of douchebags. If you look at your top five all time list of most annoying douchebags on CF you are likely to find most or all of them still play. If you look at your 2005 top 5 list of great players almost all of them are likely to be gone. (100% of my top ten list is gone.) What you get with CF is a very toxic environment. It's a lot of thinly veiled or completely unveiled OOC tirades and asshole behavior. There is very, very little role-play happening on the MUD now.
If role-play and PK are your drivers for CF enjoyment I think you should look elsewhere. Obviously the two or three dozen remaining players will disagree with me, but the two or three hundred who have left to never return aren't here to agree. I'm only here because I'm this desperate to avoid working today. :)