Maybe it has to do with where you lived/ who you ran with? Having different life experiences doesn't make either of us right or wrong. I will say that I'm from Hawthorne, where much of Pulp Fiction was shot, and saw there, and in Oakland, where I later lived, plenty of first-hand examples of what you are claiming I'm wrong about having seen. And, I did not say Jimmie was saying it in an endearing way in the film. He was upset, and saying it because he knew he had carte blanche to say it in that moment. Jules and Vince had nowhere else to turn. That said, Jimmie and Jules are clearly long-time friends, and it's clearly a word he's said to Jules before, which, in that era, wasn't perceived the way it is today.
White people said the "N" word all the time back then. I really never did, but lots of people I knew did and they did it in front of black people. Definitely not the best thing to do but they did it anyway.