I've been thinking about this after the recent it interviews and it seems SE has found a new way add social interaction into the game with the inclusion of crafters into xp parties. I can start to see why they chose to have a max of 6 to 8 people in PT, to include crafters into a party. Even if you want to just solo it might not be a bad idea to invite a discipline of the land to help farm.
Kinda of wish I was in beta now though because crafter pt's can be abusive and lead to issues with gold farmers. I dread to think of a party of 8 disciplines of the land just strip mining zones at a time leaving nothing for anyone else. There needs to be limited on how many can party up or increased failure rates for said parties.
All in all I'm very excited about the possiblities this is going to bring to not only FFXIV but future of MMO's in general.