Swearing loyalty to the Queen is a symbolic act, Layla4 and not a practical action measurable by practical results.  There are many Canadians averse to swearing the oath because of personal, family or community history - Irish Catholics and Acadians among them.  If they're not already citizens, they have to get over it in order to become one (see recent court cases upholding the oath requirement), but it's understandable why they don't do it with enthusiasm.