In most MMOGs these days you find several "forced interdependence" mechanisms. Two I'd like to disassemble are grouping and crafting.
First, forced interdependence means that at some point in the game you can't do something you need to do without someone else's help. Let's get something straight: if I want to play with someone else, I will, not because I have to, but because I want to. Forcing me to interact with other players is not how you generate "community"; it's how you generate resentment and frustration and shocking news stories about crazed gamers. I play games with people I like; I work at jobs with people that perhaps I do not. My online time is supposed to be ... what? Entertainment, or a job?
Why game developers since the dawn of EQ have tried to force player interdependence through the class and crafting systems are beyond me; perhaps it was because the only way mommy could get anyone to play with those MMO pioneers when they were kids was to force them to, and that's how they figured all relationships were forged. Look, I like to group up every now and then with people I've vetted one way or another as non-jerks; I don't want to have to pile into some off-the-rack group just because there's no way to get through the next hoop in my character's development unless I submit to some lame punk's annoying gooberage. Stop trying to figure out how to force the community to group up and just let them do it if and when they feel like it. I promise, it will all be just fine. The world won't come crashing down.
Stop putting exclusive or necessary content behind doors that can only be accessed by groups, period.
Second, stop limiting my crafting options in your ham-fisted efforts to artificially force "community". Nothing worse than getting a cool recipe only to find that it requires a commodity that only a miner can forge, and you've already filled up your two crafting professions. How about this: let me learn as many craft professions as exist in the game. If I want to spend five times as much time as anyone else working on crafting skills just so I don't have to ask anyone else to sell me tarnished brass rings, what do you care? So what? Do you really think everyone in the game is going to take the time to learn all the crafting professions?
This is why we need a new, 24/7 advancment system game; if I'm working on my tailoring skills and get to the point that I can make some cool new robe but I need a reactive agent only herbalists can generate, well then if I feel like trying to get it from other players I can, but if I'd rather invest the next 36 hours of my advancement time in getting my herbalism up to that point where I can make my own damn reactive agent, thankyaverramuch, so what? That's just that much more time I've spent exploring the breadth of the game, and advancing laterally.
Don't tell me I have to group up to get X, or that I have to go to other players to get Y; let it be my option whether or not to do it that way and get X or Y faster, or do it myself and it take longer.
I'll play with others and work with them when I &%$#%$ feel like it, not because some programmer thought it'd be good for the community to force people into each other's lives.