Yeah well, Zod and pretty much ANY villain needs to be served by the story to be made interesting.
No. Ra's Alghul was not served by the story. They made several radical changes to him so that he would fit in the story perfectly. Scarecrow served the story, aside from the 30 seconds of film it took to introduce his jungian archetypes inspired mask. Everything else made the story, that is, the narrative about Batman's journey to master his fear and become a symbol, better.
If, say, Mr. Freeze or Joker had been used, they could not have served mentorship roles, they could not have been used as well as a conduit of fear. They wouldn't have served the story. We would've had to sidetrack the story to give them origins unrelated to the story.
You can make any great villain suck on film if you're not careful (see: Venom, Two-Face and Riddler in Batman Forever, DR. DOOM).
That's not what I'm talking about. It's not about sucking or not sucking. It's about their role in the story. Is it in support of the main character's development, or are they there for some other reason - to look good/be cool in a way that is separate from the heart of the film.
For an AI character, any AI character, you have to explain to the general audience the rules for this AI character, and for a story that's not about AI, the story has to derail to explain the origin for this computer and what kind of AI and threat it is.
Compare with Zod. His origin is Kal-El's origin. No service needed. No sidetracking to develop the villain separately.
Back to Eradicator, or Brainiac, or whoever. Now you have to give him a body/form/point of connection on Earth. How can the hero come into an emotional conflict with the villain if he never sees him? Never can touch him in any way? That's why AI in movies always has a central base instead of just floating out there, otherwise, you can never resolve a storyline with the character, because they're never there, physically or emotionally.
Zod, on the other hand, obviously has a very real body.
Back to 'rad. You give him a body, then you have to explain what the body is/what it's made of, and you have to make that look cool for your action sequences. Making a body out of, say, Kal-El's ship means he's basically fighting a superpowered stroller, and you remove the ship and it's emotional impact on Kal-El from the quieter scenes.
I could do this all day. Zod has the same origin, powerset and everything, so everything you explain about Zod ONLY helps to make Superman seem bigger, better, cooler, deeper and more sympathetic. The same can't be said of any of superman's villains.
Bizarro requires not only a notable preamble for us to believably explain how they master cloning a Kryptonian but can't master cloning a human, but then we have to wait for all that to happen to get a villain that is primarily subservient and imbicilic. You need that kind of villain early in the movie to keep the action going while you build an emotional threat.
