Are you saying our societies are structurally designed to not be able to integrate/assimilate immigrants, compared to the US or Canada? Rather than the evident historical and geographical factors at work here?
Both. Of course, the comparably small size of European countries is part of the equation, but geographical and historical factors are part of what shapes a society anyway. Add to that the fact that European countries are defined more ethnically compared to former colonies, and yes, your societies are just not very good for integration of immigrants. Not saying they were 'designed' that way- it just happened because of the aforementioned historical and geographical factors.
And by the way, I wasn't speaking about the Turks in particular, though immigrants from countries which are culturally or religiously very different seem to have an even harder time assimilating, unfortunately.