I’m struggling to understand your thought process. Do you think that:

1) Mass immigration of say Bangladeshis won’t substantively change the communities where they move.

Or is it:

2) You agree that this change will happen, but you think we are morally obligated to accept those changes.

The “racism and xenophobia” angle is nonsensical. I’m a Bangladshi in good standing. I make my Anglo wife deal with all our burdensome social rules and norms. But that doesn’t mean I want more of America to reflect my culture! We sacrificed a lot to get away from a country that was governed by our culture. How can I possibly have a moral obligation to accept parts of America becoming culturally like the place we wanted to escape from?