>>89453205Rorschach would condemn the human race to destroy itself.
Veidt does, at least, offer a chance of peace to humanity.
Even Dr. Manhattan recognizes this. While exposing that Veidt's plot may not result in world peace forever, it gives humanity another chance (implying that the future is not pre-determined). To preserve this opportunity, Dr. Manhattan decides to interfere. He decides to confront Rorschach. And during their conversation Manhattan realizes that Rorscach cannot be reasoned with.
I think Rorschach realizes this, too. That he is beyond reason.
In his final scene, when he removes his mask and tears are running down his face, and he repeats "DO IT!" I believe he's crying because he knows he cannot change himself, and that he would condemn humanity for his prideful principles. I believe that he knows that he needs to die because he refuses to offer the world mercy or forgiveness.
I don't think Dr. Manhattan punishes Rorschach. Instead, I believe he obliges him.
