It is certainly crude and probably a result of laziness in speech. On the other hand I constantly hear people using the term "redneck", and "cracker". Are Black Americans more important than other people? I can think of no other reason for the distinction.
I personally think any of them are somewhat offensive and don't use them. On the other hand, I don't think they justify murder or the forgiveness of murder either.
A 1993 incident at Central Michigan University was particularly illustrative. As Kennedy describes it, Keith Dambrot, the men's varsity basketball coach, in an attempt "to focus and inspire his team, asked his players for permission to use with them a term that they often used with one another: the 'N-word.'"They agreed, and he went on to give a speech in which he exhorted them to play tougher, stating, "We need to have more niggers on the team." He later explained that he meant the word "in the sense in which it is used by my African-American players to connote a person who is fearless, mentally strong, and tough."
Word spread on the CMU campus about Coach Dambrot's speech, and he was reprimanded for his use of the word and told he would be fired if he used the word again. Kennedy argues that the incident should have ended there, since the coach's intentions weren't racist or malicious. The situation escalated, however, after a university official suspended Dambrot and recruited a sensitivity trainer for his players, sparking protesters. Ultimately, Dambrot was fired.
Chris Rock, comedian and actor:
No, white people can't say "nigger," but you can sing all the rap songs.