I was once asked the question "Do traditions not divide as much as they unify?"
I think my answer makes a good post.
Good question. I suppose it would depend on the tradition and the community. Some traditions are not exclusive in that there is no restriction on the participants (see: Commercial Christmas). But the vast majority of them are kept within a community.
If the tradition is exclusive (Christian Communion) or the community is exclusive (Freemasons), then you risk becoming isolationist and alienating. It certainly does help establish that sense of "Other" but at the same time if everyone followed the same traditions... Well, I don't think human nature would be able to tolerate that kind of homogeneity. It would be the most watered-down, lowest-common-denominator pap conceivable.
What allows tradition to survive is its genuine sense of emotional involvement with something much larger than oneself. Most traditions of the last century are currently undergoing a Darwinian process of elimination because exclusion has become the nastiest of words. Perhaps a portion of modern cynicism arises from this dearth of connection to bigger things.
Americans have a wealth of tradition that inspires patriotism; Canadians have exceedingly few and, thus, are less ardently patriotic (sweeping statement, I know, but I'm not sure how many would disagree). Is that a bad thing? Depends on how much you like your patriotism. In a sense, patriotism and nationalism are simply a larger set of community ideals with a larger set of traditions. Exclusion vs. inclusion here is far more important because when your community's population is large enough then exclusion becomes dangerous to the status quo. Those excluded may be numerous enough to force a change (see: Ghandi). There is nothing that will mobilize people like a sense of exclusion.
Tradition on its own is never a good enough reason to isolate oneself. With isolation, even ignoring exclusion, there is a terrible danger: stagnation. Without infusion of new ideas, without evolution, without the possibility of feedback, tradition becomes dogma. Unyielding, merciless dogma has long been the source of human conflict and stagnation allows tradition to fossilize into dogma. In a crowded new world we are learning how to share, dogma leaves little room for co-habitation.
I guess you can tell that I'm against tradition for the most part. On a smaller level, I am for tradition, mostly the quaint, trivial kind like the Stanley Cup or the Imperial system of measurements. On a larger scale, it doesn't really work except in a meaningless, heartless way. I think there is a need for a new human tradition but to make something universal and intimate at the same time seems an impossible feat. I think allegiances and conflicts are a part of who we are, that the sense of belonging and even excluding is fundamental to who we are. I don't think tradition should be eradicated but I wouldn't go around encouraging it either.