I suppose this goes for any writers, but mostly fan fiction writers, and Harry Potter fan fiction writers in particular.
You see it a lot in crossover fics: the author wants to move Harry from the wizarding world to Stargate Command/Stark Tower/The Shire, and one important step seems to be having Harry cut all ties with all of his friends. For whatever reason. And what I see over and over is Harry being completely and utterly betrayed by his friends.
In these fics, Harry’s friends are mere caricatures of their original selves. Ron and Hermione were just being his friend because Dumbledore was paying them with money out of the Potter vaults. Molly was promised that Ginny would one day marry Harry (again, for the money). Everyone gangs together to send Harry to Azkaban based on very flimsy evidence with a sham trial.
If you really want to write a fic about betrayal, could you at least not be so lazy about it? Do justice to the characters. Do justice to your story. People are complicated. Human relationships are complicated. Relationships can go absolutely pear shaped without one party being a Snidely Wiplash evil, and the other an innocent lamb led to the slaughter. There isn’t a single JK Rowling character who is all good (Except Hedwig. RIP, Hedwig). There are only two that are all evil. I’m not saying that any of these characters were saints, but to pretend that there is nothing good about them feels like a pretty big disservice.
But if all you want to do is move Harry from one system to another, you don’t have to assassinate these characters. They fought a war, you could at least give them hero’s deaths. That’s still a little lazy, but it preserves their characters, while giving Harry plenty of angst.
Here’s another concept: people don’t have to die or betray each other to stop being best buds. Maybe they just drift apart. They won the war, but they found out that without school, and without conflict, they didn’t really have much in common. There is still a bond that will never be quenched; there is love. But there is no need to see each other every day, or even every week. After a couple of years, they only see each other for the big events. Sometimes, they write. But they have new friends, new people that they rely on. Should Harry ever decide to leave on what could be a one way mission, his friends will be sad for a while, but they’ll be fine without him. Also, maybe the reason Harry and Ginny didn’t marry and live happily ever after wasn’t because Ginny cheated on him with half the wizarding world, but because they found that they weren’t compatible as a couple.
Maybe, after the war was over, Harry can’t look at Ron without seeing the face of the girl he loved, frozen in death. Maybe he can’t look at Hermione, because all he can think of are the horrible effects of the curses she created to kill death eaters en mass. Curses that he himself has used; that still haunt his dreams. He needs to leave, to find a life that isn’t defined by blood and pain.
I’m sure a cleverer person than I could think of a dozen other ways to separate Harry from the wizarding world without character assassination. You just need one to do justice to your characters