The damn thing should've gone like this: Jor-El finds out planet is dying at the last second cause they pillaged the planet of all its resources. Sends Kal-El to Earth, the only other planet he knew of that could sustain life. Kryptonians wanted to know coordinates, Jor-El doesn't tell them for fear of Earth becoming like Kypton. Zod is detained for war crimes in the meantime, despite his loyalty to Kypton.
Fast forward to the present, Zod finds out Kypton was destoryed. Kal-el, now as Clark, reactivates his pod which sends a becon to Zod. Zod comes in and decides to make Earth into Krypton even if it means killing all human inhabitants cause that's his prime directive. Clark, not wanting that, fights and defeats Zod. The end.
Fucking seriously, was all that other BS absolutely necessary? You could keep the whole Superman has the DNA (or whatever the fuck it was) of all Kryptonians in him making it a priority for Zod to kill him and take it...but make a revelation for the SECOND HALF of the movie!! Not the whole damn thing, which just made it confusing and generally uninteresting.
I have more gripes, but the main structure was the biggest fuck up. And those flashbacks thrown in had the worst fucking dialogue I ever heard. Seriously, what the fuck?