Didn't see the programme. Unsure what you refer to religionists and atheists for. The discomfort felt by those involved may well be race related but it isn't racist of itself, for it shows no animosity to the individuals but merely relates to the natural feeling of no longer belonging in the place they grew up, due to a foreign culture now being not just significant but dominant. One's comfortable feeling of the familiar that one uses as anchor, has been removed. It is a reason why change ought not be rapid/dramatic and incomers try to integrate into the host community rather than group together recreating the culture they are familiar with, in isolated groups. But the fact is that incomers feel more comfortable being with others who feel the same, so it tends to happen.