I don't even think you need to believe in hierarchy of marginalized people, all you need is to not want to see killing happen at home because it's icky up close and all of a sudden it makes a lot of sense.
Maybe I'm wrong but I came to this conclusion because it seems people don't care (or at least don't care as strongly) if LGBTQ+ people are killed in oversees conflicts, but care a lot about the idea it might happen in their country.