Multiculturalism Doesn't Work?

Assuming (as I do) that there's nothing as practical as a good theory, does Chancellor Merkel's pronouncement Saturday that the attempts to create a multicultural society in Germany have "utterly failed" represent a bump in the road to the happy place, a condemnation of multicultural politics, political posturing, a resurgent xenophobia, reversion to the true faith, or something else entirely (or nothing at all, philosophically)?

Considering the amount of ink that has been shed in the last decade or so building theories of multiculturalism always with an eye on the European Union, I wonder if this political event means anything at all to those theories, and similarly, if those theories mean anything at all to this event.