In singleplayer tradeoffs create replayability but in multiplayer it's alts.
That's pretty much true.
I think there is still a way to eliminate crafting alts, mining alts etc and still having trade offs, but it's a harsh solution. Quickly explained below.
Things needed:- Battle.net like account system (1 account per person, your account contains all your characters)
- Item crafted / found by character x on account y cannot be given to other characters on account y.
- Only one character from account y can be in faction x.
This way you cannot:- Gather resources and give them to your main char.
- Craft items and give them to your main char.
This would force...- ...you and your faction to buy items you and your faction cannot craft from other players / NPCs
- ...faction to look for a specific player (e.g. we need a gunsmith)
That's quick and dirty explanation. This also goes to category "just-popped-into-my-head" so I'm not surprised, if I have missed out something important. If this was combined with the system Graf is suggesting, it could be pretty cool... maybe.