Tiny idea that might have a large impact:
Relax the auto-logout and hungry/thirsty code.
When I'm at home watching my son or doing laundry I find myself needing to log out completely whenever I step away from the game, because the mud will disconnect me soon enough if I am idle for more than a couple minutes. There must be other players who are in a similar situation. If I could instead just sit idle in the game without being automatically logged out, I could play for a bit every time I had a spare minute. As it is, I log out when I get busy and then I don't even think to log back in and play just for 10 minutes, so I end up not playing at all when I am semi-busy.
Similarly, sometimes I want to play and do ranks or something but I don't have anyone to group with. I could sit idle and check who every 15 minutes, but again the game will just log me out completely and the act of logging out and back into the game is just a tiny bit of extra effort that pushes things over into the "why should I bother?" feeling and I just don't play at all. If I could sit idle longer, I could just leave the session open in the background and glance to see shouts and tells every few minutes.
TL;DR: remove the auto disconnect or significantly increase the timeout for it. Relaxing hungry/thirsty would be nice, or remove malnutrition, but that is of secondary importance. This will result in at least a few players staying online when semi-busy instead of logging out completely.
Potential drawback: you might have a deceptive list of players, for example maybe it looks like 60 are online but 30 of those are really AFK.