Some people like it. Some people hate it. I am just trying to figure out what it is.
If my neighbour came from a different country and cooks her rice in a different way, I am curious. Can I learn that? If she likes wearing unusual clothes, I am curious: I like ethnic fashion. If she looks very different from locals, as an artist, I am very curious. Could there seriously be any problem?
The problems arise when there is a religion involved. Maybe she wears a scarf all the time (or goes to a temple, never goes to doctors, prays, don't eat duck meat, etc). Maybe she thinks that it is right, good, proper thing to do and ones who don't do that are sinners, infidels, heretics, condemned? Neighbours will read this in her eyes - or just imagine they read it, but, anyway, this will be a wedge between them.
In my personal opinion, it is very difficult for a large number of believers to accept others, ones who don't believe in their gods. "Non-Christians can't do good deeds". "If they are not baptised in the Orthodox Church they will burn in Hell forever". "Their view of the world is wrong". "Demons tell them what to say". I've heard it all. Funny enough, their sacred books are on their side.
I think the very idea of multiculturalism is just a response to the last hiccups of religion. The only serious things which make living side by side for peoples from different cultures really difficult, are their believes. Believes in religious (also maybe ethnic or class) supremacy. Of course, there are cases of anti-social behaviour but "neighbours from Hell" don't need to be of different culture - every one has got their own lot. Majority of people no matter where from, by their social nature, will want to comply with neighbours, not terrorise them.
One can learn to overcome ones nationalistic or class pride. Yet every popular religion says it is the only true one, so this supremacy lies in its root. One either gives up all or the most of ones religious system - to live in real peace, to enjoy real friendship - or one forever looks at strangers suspiciousely...