It may be just game.
But I feel some guilt about such deed. I feel some emotional uneasiness or resistance to do so. And as an advlt, I am worried how kids who plays this game will feel about such deed.
So we need some peaceful mean to let unwanted dweller go away from my vault. let them walk away my vault and move to other (imaginary) vault. It may be just cosmetic change or delusion, But we need such delusion for better peace of mind.