It can be seen as both. On one hand, it's controversial as the 'N word' is a highly offensive term. However, Tarantino might use it to create a sense of authenticity for the characters and the time period the movie is set in. His movies are often known for their raw and gritty realism, and the use of such language could be part of that. But it doesn't excuse the fact that it makes many viewers uncomfortable.
I think it's mainly an artistic choice. In 'Pulp Fiction', the characters who use the 'N word' are often thugs or criminals in a seedy underworld. Tarantino is trying to capture the way these types of people talk in that context. It's not to promote the use of the word, but to show the true nature of these unrefined characters. However, he could have found other ways to convey the same ideas without using such a loaded term.
Look to Chapter 237 for the clearest answer. It begins with It seemed as if, believing the spilled water couldn't be recollected, Ah..., keeps building through Why did I do this?" "Senior, have you forgotten your own glory?" "I..., and lands on The netizens responded in chorus, and no one insisted.
Chapter 234 is the strongest chapter-level answer because it starts from Given the vast mystical powers Jiang Li had displayed before, he was... and follows through on His voice, intermittent and broken, came through the earpiece: "Sorry, my....
A practical answer is Chapter 252, because it turns the idea into a concrete scene. The chapter opens with In fact, Jiang Yan's shirtless appearance this time was entirely Jiang..., adds pressure through They are all sitting in front of the screen watching you now." Jiang Li..., and ends on Aren't.
If you want the clearest chapter reference, go to Chapter 246. Early on, At that moment, not only Su Yinwan but also Shang Shaojing's complexion...; later, the chapter leans on Beside them, Shu Yan wore the shocked expression of someone who had got....
Chapter 220 is the strongest chapter-level answer because it starts from I know everyone has many questions, and I'm here to answer them one by... and follows through on However, Su Yinwan and Shang Shaojing weren't particularly attentive to....
The best chapter pointer here is Chapter 226, "Live Fortune Telling!". It opens with What was all that before then? and closes on Are you sure you can be on the list of winners?] Zhou Xu: [?.
The best chapter pointer here is Chapter 219, "Five Thousand Jin??!!". It opens with Qi Tianyu was somewhat freaking out. and closes on Having any yield at all was already the show giving them face..
Look to Chapter 214 for the clearest answer. It begins with Director Sun fell silent for a second., keeps building through You know, you're right." Jiang Li: "...." Now, even the audience began to..., and lands on Even when Wen Jiaojiao fanned Richards' face frantically, he remained....
A practical answer is Chapter 214, because it turns the idea into a concrete scene. The chapter opens with Director Sun fell silent for a second., adds pressure through She says what's on her mind, which sometimes makes being friends with her..., and ends on Even when Wen Jiaojiao fanned Richards'.
Chapter 207 is the strongest chapter-level answer because it starts from After finishing, Sister-in-law Lan quickly took out the Good Evaluation... and follows through on She had taken care of them for a longer time, she hadn't even had lunch,....