While I understand your point--justified is not the right term to apply in this situation--I think your analogy fails for a single reason. A heart--which is synonymous with one's ability to feel emotions in the mythos of Kingdom Hearts--is not the same as a leg. I hope that losing your leg would not remove your ability to have a conscience. Nobodies have no heart and thus no conscience, so the circumstances are different. No more justified, but different.