Very well said, Dr, but I will also add that RotO pretty clearly states what Diana's code is, in writing. She has nearly everything taken from her and she STILL doesn't kill in vengeance.
There's also a common mistake going on in this thread (not your post), that because a character says something, it reveals either 1) the writer's viewpoint, or 2) objective truth. I don't write like that. I actually agree with the point made earlier that Diana SHOULD give some thought to the notion of AI being a form of sentience. I will also concede that Diana should know better, particularly since she knows the Red Tornado and considers him a friend. I don't disagree with any of that, in fact, I'd say they hit the nail on the head.
But what she's saying is what's going through her mind at that moment, in battle. It's neither my viewpoint, nor is it necessarily objective truth. It isn't even necessarily the choice she would make at the crucial moment, since we've just recently seen her pull back from killing someone she had sworn to kill.
I think that's part of what makes fiction enjoyable, is the clashing of people's subjective opinions and reality.