Why we shouldn’t use made-up history to excuse real life decisions: The Thermian Argument, (Youtube) Minisode by Folding Ideas. I very much enjoyed this as an exploration of what’s wrong with the argument, “This character’s attitude isn’t problematic because because it’s consistent with their backstory!”
(When pointing out problematic elements in fictional stories, some fans will excuse these elements by saying “well, it’s true to the story” or “that’s just part of the character’s/world’s/universe’s history.” But the story, and the universe it’s set in, are made up. They’re the result of decisions made by people in the real world.)
The fact that people create universes from which problematic elements logically follow isn’t a justification. It’s the issue.