I get the moral hairsplitting as I used to say it was okay if they had committed truly heinous crimes but now I just say no under all circumstances unless they were threatening my life, I try to look at the bigger picture.
I don't know how I would feel if someone killed someone close to me... so it's an armchair conclusion. I have seen wardens interviewed and they say people use the "closure argument" but they said from what they witnessed repeated over the years that after the execution the victims were disappointed as there is never closure that way. And frankly, I think closure is a personal choice and solely an internal process involving no one but self.