Superman has killed Zod in the comics a few times, The first time he did it he killed all three phantom zone criminals with Kryptonite, a slow and agonizing death. In the 78 movie he pitched Zod into a bottomless pit after crushing his hand even though he had been rendered powerless. Killing Zod couldn't be more true to the character. If anything the neck break in MOS was the most humane way it's been portrayed so far, but that is neither here nor there. I am talking purely from a design standpoint.
For decades now, the first and greatest hero has been a joke. An archaic costume deemed silly and ridiculed endlessly by the public at large because the relevancy of the design no longer exists. The original design was based off of the costumes of wrestlers and circus strongmen of the turn of the century. pinnacles of strength of the time. That time is no more, no one wears that anymore and every other superhero has been allowed to move forward, to evolve. most every other hero that had the trunks over tights look ditched it almost 20 years ago.
Superman had finally gotten past that, his costume was finally given a more contemporary upgrade, that managed to still retain it's iconic look. Now here we are again, back to square one with a guy who doesn't realize that underwear go under his pants.