You are what's right with this world. Maybe if someone I loved was murdered I would feel like making them suffer. But executing the criminal who did it wouldn't erase my pain in anyway, it wouldn't bring back my loved one, there is no way to go back in time. On the other hand, if I really wanted revenge I'd rather do it by my hands and face my sentence than ask the system to practice my revenge under the name of pseudo justice.
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you