Well.. it makes sense.I don't know. I tjink tension is caused by people being out of their comfort zone and feeling unsafe when others around them don't look or act like them, and particularly speaking a different language. Have you ever experienced cukture shock? I did, in Japan the first time I went - and that's despite speaking Japanese and knowing largely what to expect. It's like that but because it takes place over a longer period of time, it's more insidious.
As an example, I stayed in the Marble Arch area of London some years ago, and the area was largely populated by people of Middle Eastern origin (at least, it was then). People were speaking Arabic, shop signs were in Arabic, and people dressed and acted as they would in the Middle East. There were very few people of obvious white British descent around. I felt uncomfortable, and that's despite the fact that I grew up in the Middle Eas.
Whereas going into London's Chinatown, which is in the centre of the tourist district, where there are lots of British people around,I felt perfectly comfortable despite the shop signs being in Chinese (which I don't speak), and the locals speaking either Chinese or heavily aaccented English.
If you go to England you expect to see English. Ain't that the logic?