It's still harder to find people to do things than it is to do the things in the game. It would be easy to implement a signboard system where people could volunteer to help others in exchange for points that would in turn allow them to post for help. Weather it's abyssea seals, Dynamis wins, Abyssea ZB wins, Voidwatch, Missions, etc you spend all your time trying to find people to do it with and for better or worse it's over in 5 minutes. Thiat is assuming you can find people to go with to begin with. I have been in more parties that broke up because they couldn't find people than PTs that tried and failed in the past month.

People keep quiting and coming back. You obviosly have a game people want to play. Give them a reason to stay.