Thinkers say that justice needs to be administered in love. Both are to help the person flourish. You cannot love a person if you condone their being treated unfairly. Justice becomes too mechanical without love and thus risks making society worse. Love without justice turns into childish sentimentality. Justice demands that while a dangerous person has to be punished, it is important to bring mercy in where possible. Justice and love go together.
Justice is too much like the difference between hill and mountain. When something is seen by one as a hill and another by a mountain there is no way to be sure. Sometimes it is obvious but most of the time it is not. Justice could be objectively right perhaps – but that does not mean it has useful or sharp boundaries or that accurate interpretation is feasible. It does not mean it is clear in itself or that even if it were we are able to be clear on it. Math can be objectively true but it is not obligated to tell us that 1 and 1 = 2. You can imagine a universe where 1 and 1 are somewhere between 1 and 3. That is still correct but not precise. Same model.
The confusion risks people acting as if they are more confused than they actually are. They seek an advantage in that.