Segregation = Multiculturalism?

In his 2001 paper, Immigration and Housing in Gateway Cities: The Cases of Sydney and Vancouver, David Ley, along with Peter Murphy, Kris Olds, and Bill Randolph, puts forward the idea that ethnic segregation is a natural and inevitable process. He argues that through geographic isolation ethnic communities are able flourish and create strong cultural identities. According to Ley, it is only through this process of ethnic segregation that a truly multicultural society will be formed. For him isolation allows for a society of difference not assimilation.

As valid as this idea sounds I find it disturbing. To me it says: we can all live happily in isolation, why bother trying to resolve differences? By living in isolated communities we will have no differences to resolve. I find this approach lazy. It assumes that we needn't work towards cultural integration because things are best the way they are. The label multiculturalism is used giving the whole isolation idea credibility. Ley's argument is simply an easy, guilt-free solution.
Surely there must be a middle ground between isolation and assimilation.