When you're this far down the rabbit hole, it's not morality as much as it is hotness. There's a lot involved in how people get into this: if they self-insert, where they self-insert, how they self-insert... so how the hero acts is pretty vital to how hot they find the scene.
I, for instance, hate lethal violence. I could write like goddamn 5 pages about why that is, but I won't cause no one cares. I recognized the art of the runark girls because I saw it before, part of it is sitting on my hard-drive. The parts where the violence isn't obviously lethal.
Take anyone saying "don't kill them" on this board less as someone trying to tut-tut a fantasy and more someone screaming in the comments of a porn vid that there's no anal.