Although I haven't personally used the word "obsession", coming from a Scottish perspective I do find the whole "clan" thing a bit of an irrelevance and only ever considered it when choosing a tartan as it seemed like a good idea at the time rather than just selecting one at random. If I had not liked the tartan, however, I would have had absolutely no compunction in choosing another as I do not accept for a moment that there is an inviolable right to any non-patented or non-family tartan. I am very aware, however, that absence makes the heart grow fonder, that distance can obliterate memories of hardship and suffering and give the individual a pair of rose-tinted spectacles about many things others might prefer to forget. As a result, there are probably no greater adherents to the clan system, no bigger consumers of shortbread, haggis and scotch whisky, no more enthusiastic attendees at Burns suppers, no more assiduous exponents of highland dancing, piping and the learning of Gaelic than are those from the great Scottish diaspora, many separated by several generations from their roots. This is not to say, however, that any of them would actually consider returning to live the dream, preferring instead to pontificate from afar.
For a Scot born and bred and actually living in the country, however, clans have very little relevance beyond the name on a nice tartan and to bend the knee to any upstart calling themselves a "clan chief" would be totally unthinkable.
That is where I come from but I know many here think differently and I have no wish for them to curtail the innocent pleasure they derive from the feeling of "belonging" which they must enjoy, especially in some modern societies where anonymity and social isolation have become more common. As long as they don't take the next step down the road and start believing "that tartan is mine and no-one else must wear it" or worse still "my clan right or wrong". That way is the way of division and strife.