There is always the desire to preserve and assert one's own identity. Everyone has such desires. They manifest differently, according to whatever influences were around you in your formative years. It's not something that should arouse hatred and conflict among people, it's something that should arouse curiosity about different cultures and enjoyment of the variety of the greater world out there.

To put it another way, what's more interesting...a garden with 35 different kinds of flowers in it...or a garden with only one kind of flower in it?

What's more interesting...a jungle with thousands of different kinds of plants in it....or a well-organized field of rutabagas?