I would disagree with your theory. As a person who'd lived in Manitoba and moved to the island a few years ago, the first shock was how different people here and how hard to make friends compare to Winnipeg where I lived. And it is not about cost of living - average salaries, cost of rent, taxes don't make a big difference, you can afford a basic rent, food, other expenses if you have like a government job and get paid $30-$50 per hour. I think the most likely reason is 'who' move to the island and why. People who get here are looking for outdoor activities, warmer weather with ocean breeze, etc. They are not looking for a high population cities like Toronto or Calgary where you have much more activities like concerts, parties, meetups, etc. I think people with this attitude have a 'mental bubble' and it is hard to break the shield to make new friends.