Actually, if you take the time to think about this, you will find that there are many cases like this in our society. Cases where unpopular words or phrases, are replaced by less ugly words, or phrases, to make the topic seem better.
-Manipulation and persuasion
-Black and African American
-Homophobic and traditional
-Torture and enhanced interrogation methods
-Terrorists and hate groups(like the kkk).
-Old people and seniors
-Murderers and military veterans(or heroes)
-The right to oppress and religious liberty
-Indocrination and values
-Prostitutes and working women
-Creationism and intelligent design
-Believers in no God and Atheists(non-believers)
The latter words, or phrases, are the euphemisms. The euphemisms are used as replacements to help make things seem better than they are.
And there are also cases where different words, or phrases, are used to make something look worse. A good example of this is when people immigrate to America without going through the legal process, they are sometimes referred to as illegals or aliens. This kind of rhetoric is used to make them appear more exotic and inferior. It is used, usually by politicians, as a way to "other" people who have immigrated to the U.S without completing the legal process.
But its all the same thing. Word choice is very important when attempting to manipulate, or persuade, people to conform to your beliefs or ideas.
Revenge in itself is a pay back. If there wasn't any preliminary event that hurt one in some ways, revenge wouldn't happen.
Justice,on the other hand, is the establishment of fairness, it doesn't need a previous event to happen.
Revenge is associated with people's mentality and their own actions, whilst justice can be performed through law, equally and fairly.
Revenge isn't justice, and justice isn't revenge.
"Revenge" would imply an intention of making a wrong-doer suffer based on personal experience and - sometimes temporary and irrational - emotional satisfaction in some sense. There are little limits to the intensity of the punishment or the feedback it would generate.
"Justice" would be brought upon the wrong-doer based on commonly agreed upon standards and would benefit both oneself and others. The intensity of the punishment would ideally be equal to that of the wrong done and would decrease the possible feedback it might generate.