I was thinking that maybe justice only prevails thanks to another phrase, "history is written by the winners". History, official history, is indeed written exclusively by whoever won the argument/war.
I think not one person would ever consider themselves unjustified, or that they are the "bad guys" that should lose. If someone does, please write to me because I would love to talk to you.
Anyway, so basically, -we- are always the "good guys" and -they- are always the "bad guys". When we win, the good guys win. Then, we the rightful winners go ahead and write our story, our history.
In the winner's history, justice always does prevail.