The question says it all. A member of a tribe doesn't respect self before clan. While those of us raised in the modern "Western" culture see the rugged individualist as the pinnacle of social evolution, this has been a relatively recent phenomenon - and not all that wide-spread. Most of the world still has much stronger "family values" than we can even conceive of.
It's common in the US for people to pick up and move to a different state for the sake of their career or education. No one thinks any less of them, and they are encouraged, because this is what individuals are supposed to do. Moving away from your roots, however shallow they may be to begin with, is seen as right and proper. After all, you wouldn't want to be tied down to your family and friends. Those coming from more traditional cultures, even in Europe, may shake their heads in wonder at the apparent lack of feeling and connection we display.
But what does this have to do with shamanism? I'm glad you asked! In a traditional setting, the shaman works in service to his or her community. So what happens when there is no community? Does the role of the shaman simply evaporate? No. If anything, the need is greater. Part of the work of a shaman is to remind the people where they come from; to help them develop their spiritual roots and to recognize the gifts of their ancestors. These are needed more by our "rugged individualists" than by anyone living in a tribal culture.
While the shape of society has transformed, the substance of what it is to be human has not. To a certain extent, the function of a shaman reflects the context in which he or she works. If their is a coherent community, it makes sense to work within that structure. However, if that community does not exist, the shaman still has work to do. What that work is will reflect the nature of the society we find ourselves in today.
There are those who believe that since the definition of shamanism that we "Westerners" developed from observing indigenous healers included "service to community", there can be no shamans without that element. Some even go so far as to claim that the practices of the shaman "belong" to the indigenous cultures in which they were found and that for us to use them is to steal them from the source. I would argue that this is a misunderstanding of the nature of shamanism and of the human condition. Shamanism is rooted in the human experience. The fact that people in our modern culture can be effectively healed by shamanic methods is one proof that they are valid and appropriate. The fact that moderns can also become effective shamans is another.
This is not to say that all modern "shamans" are relevant, valid or even sane. Nor do I approve of the tendency of some to wear the trappings of other cultures - dressing up as native Americans or other tribal people - and offering their traditional teachings for a fee.
An effective shaman is not just someone who has taken a few workshops and uses a drum to put their clients into an altered state. While the cultural setting has changed, the shaman is still a person who has passed through initiation and transformation; who has met their demons and survived; who speaks with the spirits and who is able to use that experience to assist in the healing of others.