In these days of aggressive nationalism and communities divided by ethinicity and religion, there are some liberals who yearn for the old days before multi-culturalism, when the idea of the world being a melting pot of coffee-coloured people seemed a great idea.
I suspect that a world of coffee-coloured people would be a world of shoe-removing people. Simple demographics would ensure that the mass of people in Asia would ensure the prominence of the custom of removing shoes in homes.