I imagine that a lot of people who left over not agreeing with how the game was being managed and developed simply haven't kept it on their radar. They won't know that Justin™ has left, that development has improved, that balance has been worked on significantly, etc. Hell, they might think the game's finally died for good since they left.
Hence, why Hidamari's idea with the email newsletter should be seriously considered.
As for what keeps me from logging most days is also, simply, the lacking activity. I, like many of the really old vets here, have very fond memories of the golden days, when the server was at a constant 200/200 and then even 225/225 during afternoons and evenings. When I look at the player list now and see numbers ranging from 10 to 50 (on a good day), it's just very disheartening. Odds are, I won't find any meaningful interaction organically and will have to go out of my way to contrive a reason to meet people "by coincidence."
Add to that that, now that the community has shrunken considerably, I can't help but notice that I not only keep running into the same few characters again and again, but that it's also just the same small group of players between them. It gets old fast and when, despite my best efforts not to get particularly involved with players ooRPly, I do form a grudge against a player, it really drains the fun out of logging.
Technically, the game is in a better state than it has ever been. We just really need to let people - old players and potential new ones - know about it. And those of us who are still here need to do our best to be welcoming to new and returning players and provide as pleasant an environment as possible.
Edit: I do still log almost every day. But some days it's just really hard to get myself to do so.