I think it's the disconnect that throws me off

In Superman 2 he saves the humans and beats up the bad guys, it's consistent(they even point out that his weakness is that he cares about humans and use that to pressure him resulting in him making the choices he did).

In Man of Steel he barely tries to stop the terraforming device causing thousands of deaths through ecological disaster before fighting Zod happily bringing down skyscrapers. It's only in this one scene to save 4 people despite the thousands already dead due does he decide to kill Zod, only for him to be upset over it. He's not upset over the millions of people he sacrificed trying to talk Zod down since the teraforming device is causing tidal chaos and tornadoes, or people who died when he punched Zod through a skyscraper bringing it down atop hundreds of people, he's upset that he killed the last of his kind of save just 4 people.
It just doesn't add up to me, if superman wanted to save people then he should have been trying harder to minimise deaths from the start, but instead he only decided to put an end to Zod's death when he saw a scared family up close, which just doesn't feel like the same guy who constantly gives up his attempts to make a new secret life to save anyone he can from the start of the film.