Jeff says it more succinctly and precisely than I can:
The boutique multiculturalism that the West has dabbled in with such self-satisfaction, then, is dangerous insofar as it appears to promote the principles of a multicultural worldview that, when push comes to shove, it cannot—and should not—actually support. That is to say, by promoting the idea that individual cultures are the province of those who belong to them, rendering outside judgments about the beliefs and practices in those cultures at best presumptuous and at worst colonialistic (after all, in a world where “truth” is contingent upon the consensus of given interpretive communities, there are no immutable laws beyond those made by fallible man), Western culture has set the stage for its own inevitable hypocrisy when it is forced to draw the line at a point where Otherness is truly, rather than superficially, defined.
Honor killings are one such point. Female circumcisions are another. And both, in my estimation, show up the folly of building a social organization around a principle that must, at some point, be arbitrarily subverted by those who have claimed all along to promote it—else the host culture be forced to surrender to the cultures it has claimed selflessly to accomodate. At which point boutique multiculturalism is replaced by strong multiculturalism, which is the only multiculturalism that carries any real force to begin with.
And strong multiculturalism is, in certain respects, very much akin to the will to power I’ve talked about in terms of interpretive communities and identity politics: for instance, once sharia law is “accepted,” that ascendency would snuff out the rights of those who don’t wish to practice it and would then set itself up as the dominant social narrative. Which is why the Pandora’s Box of strong multiculturalism should never be opened—and why people like myself are wary whenever we see boutique multiculturalists playing around with the latch.