This is moving on to a different issue now, but an interesting one.
We can exclude films straight away from your claim. The N word's use in films is art imitating life.
By using the use of things in film as a reason why we shouldn't complain about them we'd also have to accept rape, murder, paedophilia, and talking animals as things we can't react negatively to.
In music... Do you honestly think that because rappers (who have mostly grown up using the N word in the same way we would use "mate") use it it means EVERYONE else should be able to use it in any way they want to? And that people shouldn't be able to object to it being used by others?
Quite an important thing that people who use your same argument are overlooking is... in songs, the N word being used is "nigga". There's a big difference between nigga and nigger, they are two entirely different words that carry entirely different meanings.
Life is full of rules for one group of people and other rules for another group. Part of being an intelligent human being is knowing what you can, can't, should or shouldn't do based on your sex, age, race, religion, position, etc etc.