I am not a supporter of revenge. Not at all.
However, I have been guilty of it in the past- once (years ago) I was even quite creative plotting and setting up a revenge situation, although I have no way of knowing what ever came of it. And I realize now it was wrong of me.
Actually, I knew it was wrong when I did it, too, but I did it anyway and felt quite pleased with myself. I am not perfect, but I try to do better all the time. I wouldn't feel good about myself if I did something like that now.
So, I don't advocate revenge, but I can certainly understand it.
In the same way, there are people who do things so bad that I can't help but feel a bit of pleasure when someone else gets revenge on them.
I realize I am probably wrong to feel satisfaction when a bad guy "gets his". Even when it is someone who, from personal experience, I feel "deserves" whatever he gets.
The problem with revenge is that it is an initiation of force. It doesn't matter if it is called "punishment" or "justice"- if you are not in immediate danger of being violated, you become the aggressor if you attack.
But, I will say this: in a case where the history of the victim of revenge makes me sympathize with the person who got revenge on him, he shouldn't come to me seeking my help in arbitration, because I would be biased. I know that is probably also wrong of me.