I do not think we are suggesting Muslims can't integrate into a Western nation's culture. The concern is with those who do not.
Who is this we to whom you refer? Dogmaphobe is clearly saying that muslims can't integrate into a western nation's culture. Gipper seems to be of the same opinion as well, as does the author of the OP.
Is there some other we you are speaking of?
What percentage of muslims do you believe do not integrate?
I would suggest that America's experiences with integrating diverse populations of refugees suggests that there are some initial growing pains, but that most immigrant groups assimilate fairly well.
Remember the Cuban Refugee Crisis? There were more than a few Tony Montana's in areas with high populations of Cuban refugees resettling, but things quieted down within 5-6 years. Now Haitian refugees are being integrated in the same way...lots of haitian crime, but they will eventually settle down, as well.
There are always growing pains when we see large population shifts like this.