I think I wrote something along these lines in a comment somewhere last summer, but I guess I better post about it again, because
people: still assholes, film at eleven.
Cut for discussion of the Holocaust, and of how not to respond to people you've triggered, and general tl;dr. Same warnings apply to the link above.
HERE IS A VERY IMPORTANT ANNOUNCEMENT FOR YOU, INTERNET: Fanfic does not work like original fic. It doesn't. They both serve a purpose, and the line between them is pretty blurry sometimes, but they are not the same fucking thing and you cannot approach them, as a writer or a reader, the same way. I know this is a really difficult concept, but just bear with me, okay?
Okay.
Now, say you decide to write a story set in Buchenwald in 1941 in which one of the Nazi guards falls in love with one of the prisoners. Does this offend me? Yes, absolutely; for one thing I have less than no interest in fiction that wants me to sympathize with a Nazi angsting over the revelation that HOLY SHIT, GENOCIDE IS BAD, GUYS. Do I think the idea is edgy and kind of dumb? Yep. But am I at least willing to believe that you thought you were starting out with a legitimate, thoughtful story idea about Tragedy and Love and Redemption that might add constructively to the canon of Holocaust literature? Yeah, sure, I can believe that. Because original fic doesn't have a set starting point; you could start out with characters or with a story or with a world, any way works, and I have no way of knowing which.
Now say you decide to write this story, but you happen to be really fond of the movie Inception, and for some Godforsaken reason you choose to express this fondness by changing the main character to a concentration camp guard named Kolben who falls in love with another main character, who is a Jewish inmate.
Now that? That is a decision you've made, in the course of a creative process, and if there is anything that a year and a half of art school has beaten into me, it's that when you are creating anything you have to make thoughtful decisions about everything and you have to be able to back that shit up, because every decision you make about a work has a context and everything about that work is going to affect how readers experience it. Like, if you draw a page of a comic book and all the panels are in color except one-- that's a design decision. You need to have a good reason for that, because every one of your readers is going to notice that and assume it means something that that one panel is in black and white.
Twenty to one-- because this is my experience of fannish thought processes-- the writer, or in this case the prompter, didn't start out with a serious story idea about Tragedy and Love and whatever the fuck. They started out with the characters, Arthur and Cobb, and the story idea followed from the desire to write about those characters. Which is bullshit and makes me angry, because yep, you are taking a massive RL trauma and using it as an excuse for manpain, and it is really difficult under these circumstances to believe you when you say you set out to write "a character study with value."
But I will give you that one-in-twenty benefit of the doubt, writer; I will even pretend you didn't get the idea off the Inception kink meme, which makes those odds even steeper. Let's say you wanted to write your story idea about tragic offensive love at Buchenwald, and then you went "hey, I want to put Arthur and Cobb in this." That is a creative decision. That is a FUCKING HUGE creative decision, to set out to write what you claim to think is serious thoughtful literature, but then to decide that you'd rather copy/paste in your favorite fannish characters than use original ones. It's like, on top of offending people with your premise, whacking them over the head with a mallet and going "FYI, my desire to write about Cobb Kolben angsting is a priority on the same level with my desire to write a serious character piece about the Holocaust." If your thought process actually went that way, well, that's just fucking awful. No amount of thought and research and work can possibly make up for that.
But hey, everyone makes mistakes. Even ones, like this one, that are so completely egregious that it becomes really difficult to believe they weren't intentional. So I prefer to judge people, not entirely by their fuckups, but how they respond to having their fuckups pointed out to them.
And if your responses consist of claiming that you were trying to write seriously about the Holocaust and people you've offended should appreciate that, or that your prompter loves it and no one else's feelings matter, or that as a POC you don't think you'd be triggered by stories about slavery and therefore Jewish people shouldn't be triggered by stories about the Holocaust? Well, congratulations, your pretensions to be writing Srs Literary Slashfic For A Cause now hold absolutely zero water.
I have fucking had it with humanity, seriously. No one ever fucking learns.