Mr. Ibbitson has conflated two concepts into one - multiculturalism and immigration.  There is a linkage between them but they are not the same.  Immigration is an aspect of economic policy.  Do we need more people to sustain economic growth?  In the past - yes.  But now we are living in a 4th industrial revolution, with projections that many jobs will be displaced by AI and the digital economy.  In the future we may have too many people rather than too few.  Hence, caution in immigration policy is indicated.  As to multiculturalism, it was created for reasons of national unity - to submerge the English - French struggle for dominance in Canada that existed since the days of Lord Durham.  As a policy it worked - the 1995 Quebec referendum was won by 50,000 federalist votes - mostly anglos or allophones, and national debates today are about our exotic neighborhoods.  But the concern about ethnic enclaves is legitimate.  More resources should be focused on the integration of newcomers.