They have every reason to be worried. Everywhere Muslims and non-Muslims have come into contact, Muslims have initiated conflict. Why should South Korea be different?
“We have had no contact with Muslim people before, but we know that they all have big families and they bring their own culture instead of trying to adapt to the place where they live, so people here think that they should have gone as refugees to other Muslim countries.”
This is an accurate observation followed by a sensible recommendation, but in the West it would get this man charges of “racism” and “Islamophobia.”