As I type this, there is not 1 reason to do anything (other than PvP and you dont have to have it there). 9D used to have things to where you needed party's to do things, all the way back to SCM and GCM to LLGC. Now as we play and do things in game, there is no reason to do it with party's. Clan Dungeons you dont have to have them, but we do. The rewards quest can be done without a party, but we choose to do 4 man runs all reds.
I'd like to add: - allow inter-clan buffing (white can buff black or vaga & visa-versa..) - allow mixed, or 'Raid' parties I feel these will promote activeness, and will reward the truly active players, as the current system makes the 1'Xers (those whom play even if there's no rate boost/s) suffer.