For a start,the "N word" has acquired the tag of racism though it is still used seriously by black people in the Deep South, and the related, though now less offensive, word negroes was used by Martin Luther King, but that, in the singular, is barred by our censor filter. But because the N word was used insultingly by so many whites in the US, it is now forbidden, and the other word has, curiously, also come into disfavour.
Old people are more racist, and it's not a question of whether they use outdated words or not. They were brought up with the idea that black people were primitive and inferior to whites ( and British people were superior to everybody else!). Indians were superior to blacks, and made good civil servants for the Empire, but were still inferior to us. And Jews? Well, some of them were clever, but all were dishonest and they all stuck together. "By Jove, I wouldn't have a Jew in my golf club" was the attitude, and it was carried through. Many clubs would not admit Jews ,some had a quota. One to the north of London had neither policy, with the result that it rapidly became virtually a Jewish club (but it was a lot more luxurious as a result!)
And the whole thing was backed by a simple, apparently natural, distrust or defensiveness of anyone who is not like us.