So something I think that contributes to mafia games becoming less-desirable is the village leader system. I understand its usefulness, of course, but it's something that can both equally help and hurt the game.
The help, of course, comes in the form of making your faction stronger and giving you a better chance of winning. Dur.
The hurt, however, is that the non-leader players are subjugated by the leader, and lose a big chunk of control over their part in the mafia. If you lack a night action (fairly rare now, but not impossible) then you're basically just a vote (or Mayor, if you're cool).
If you do have a night action, though, you can become little more than a tool. Some people are cool with that. The problem is that people without all of the info can't make good informed decisions, but informing them can compromise your faction blah blah blah.
Anyway, something to somewhat decentralize the leadership of a faction without easily giving away what factions were what would probably help boost activity, I think. Easier said than done.
But it certainly made Viking mafia more fun for me when I was a part of the decision making process with 1-2 other people. FF5 mafia is looking like it'll actually do something along what I suggested, but I dunno if the alliances will be more public than what I'm saying.
] <MK_Ultra> that kid is asking to be molested