I'm not so sure that's true. Consider:
"All <n-word>s need to go back to Africa." (clearly and overly hateful)
"All black people need to go back to Africa." (still hateful)
"All African-Americans need to go back to Africa." (All words are accepted, but the notion is still rather hateful)
No matter what words one uses it could be considered hate speech by today's definition. Disclaimer: I do not nor do I advocate using racial slurs, the stub in here was just to prove a point.