No matter people's opinion of Tarantino, as a white writer who just finished a novel about an alternative world where slaves are freed in 1778, I found it extremely important not to use that word anywhere by anybody in the novel.

White people shouldn't use the word, period, for any reason, even if it is meant to "make a point" about other white people. That may seem unfair to white people but it's not.

It's lazy writing. It isn't needed. There are a million ways, at least, to demonstrate racism without using the word.

In fact, I'd argue that using it gives the white writer a bit of a cheap thrill when they find an excuse to use it.

Your feelings are justified, IMO.