Every book has to be taken in context. Every idea, in fact, has to be taken in its own historical context. Look at some required reading such as Tom Sawyer or Huckleberry Finn. Nearly anything by Hemingway. Melville. Or really anything from the early to mid 20th century and you will find N-bombs as well as what was considered correct language at the time: negroes, colored, and finally black.
Obviously, it would be inappropriate now, and the correct term is African-American, but no one is going to go start revising great literature. In 50 years, African-American may be considered a hateful, racist term for reasons we cannot yet conceive.
Everyone is a product of their own tiny bubble in space time, and only the brightest can see outside.