Originally Posted by
Cilia
Computer programming... isn't that simple. You could program Zodiark to stop the Sound, but given they didn't know what was causing it, that would leave him with a lot of leeway in his functions. Think of it this way: Ramuh was created to be the Sylphs' sage protector, and he does no more and no less than that - but this leaves him at odds with the Spoken races at times. The guardian becomes a destroyer.
While the Ancients were well-versed in creation magicks, it's unlikely something on the scale of Zodiark was ever attempted before. The Amaurot recreated by Emet-Selch was made from his memories of the city not long before the Sound reached it, during which Zodiark was summoned in desperation. The Akademia Anyder, where creation magicks were studied and developed, has Guardian Force Quetzalcoatl as the final boss - and it's implicitly the prototype for the primals we're familiar with.
Long story short... Zodiark was the product of creation magicks, but something on his scale was never attempted before, and if you want to compare it to computer programming the likelihood of tempering being a "bug" they didn't work out (because they had no time, and in their reteachings to Beast tribes is advantageous to their goals) is pretty high by my estimates.