It's almost as if it matters who said it and what the context/intention was. Wild.
The Wire is telling a story about systemic racism and a broken political system. It was trying to be true to life. The reason I don't remember any individual instances of anyone saying the word (it absolutely was not used excessively, that's absurd. I'm not sure it is ever even said by a white person), is because it wasn't shoe-horned in for shock value.
Pulp Fiction did not need QT to be a character at all. It did not need QT's character to make bad jokes using the n word with a 'hard r' at all.
He wrote the movie. He wrote himself into it. He wrote himself saying the n word several times for no reason other than shock value. This isn't even close to the same thing as The Wire. I honestly can't even believe that I'm having this discussion.
I'm actually kind of concerned for you that you can't see this. Why are you so intent on defending blantantly racist bullshit? It's weird, dude.