Why do we enjoy seeing justice done in real life and in fiction?

I reckon it is because we want life to be fair and predictable. Otherwise, we feel anxious about our future. 

We are taught that fairness is good, as children and as adults. I often hear the term equity in the workplace. 

We want to be fair, and we want to be viewed as fair. Naturally, we want others to be fair.

Our desire for justice can lead to a desire for vengeance. When a person who has acted unfairly suffers a bad outcome, we may take delight because we want the person to experience some of the suffering he has inflicted. When Ted Bundy was executed in Florida after murdering dozens of women, people danced and shouted in joy. 

Our ideas about what is just are learned, so what seems just to me may not seem just to you. For instance, when Walter White in Breaking Bad lets a highly troublesome heroin user choke to death rather than saving her, is justice done?

Our desire for justice can also be affected by our relationship with the wrongdoer. We sometimes accept injustice when it involves a person we love escaping a penalty for misbehaviour. 

When justice is not done, we cringe. A New Zealand psychiatrist has been accused of torturing a huge number of youths placed in his care decades ago. Now that it is possible for the many victims to seek justice in the courts, it is too late. The psychiatrist is old and demented. He will cheat the gaoler — one of the luckiest outcomes ever from dementia.

We see that life is fair sometimes and not at other times. I comfort myself about the unfairness I witness by thinking of the few times I committed a minor crime or wrong and paid no price for my misbehaviour. Life often gives us second chances. The better folks make good use of second chances.