Abuse of Language

Nowdays abuse of language has become a fashion. One thing that I really can't stand is "two wrongs don't make a right".
First of all, there are times when two wrongs don't make a right. For example when a dog bites you, you don't bite the dog back. But when that happen I guarantee you there's nobody giving the "two wrongs don't make a right" lecture.
Second, is it wrong when you want to take an eye for an eye? It's even in the Good Book and it's one very basic principle of all laws in history, which is one key element to keep peace and justice amount us humans.
So here comes the third, why do some people make the judgement when you do anything back to the wrong doing it must be the second wrong? Is it wrong to slap a person who's sexually harassing you? Or is it wrong to fight against Japan when Pearl Habor was attacked?
Honestly, when someone says "two wrongs don't make a right" is when the person can't find any actual reason to protect the person who violates others from being punished. And this is abuse of language, in the worst possible way. You only say it when A flips at B with no reason and B shoots A in response. It's "two rights don't make a right "when and only when the victim of the original wrong doer is either delivering much larger damage in return when the circumstance doesn't justify it, or is doing something anti-human like biting a running dog to take the revange.
So people, next time come up with better excuses, or at least make a better analogy.