Originally Posted by
exile001
Personally, I love it in a bittersweet way. It's a deliberately very sad moment rather than one of triumph.
And lets not forget, it wasn't just that they swore to regain their powers and come to Superman's Earth (a real threat, as Superman himself has already been transported to their Earth), it was also that they'd utterly destroyed their Earth so would likely have just died slow, agonised deaths. To a degree, Superman was showing mercy.
Tie that in with their being the first Kryptonians Superman ever met so, acting as the last line of Kryptonian justice, he's extinguishing the final remnants of his home world. It holds a lot of weight for that version of Superman, who had never encountered anything close to that threat level, and is pretty tragic overall.
They also added more than enough whistles and bells to say they're reflections of reality that might have been rather than actual main universe people to give a little distance. There's a big difference between this and, say, the Max Lord killing.
I actually love seeing what three completely unrestrained Kryptionians could do if they wanted to destroy a planet. It's something you can't do on the main Earth (which leaves certain writers incapable of writing Superman foes with any real bite) so it's a stark reminder of how lucky we are Superman is a force for good.
I do think it adds an interesting layer to Superman to think that he will kill if he feels there is absolutely no other choice because the stakes for him a usually extreme (he regularly faces things that could destroy the planet), it removes a naivety from him, and yet he consistently finds ways not to do so. The same logic was applied to Doomsday (although a seemingly mindless beast is less morally questionable).
I like the idea that he can kill and at every chance chooses not to take that option. He decided that killing is abhorrent, and not just as an external concept, but because he was forced into such a situation and that he had no other choice is anathema to him.
He is a good man who believes anyone can be redeemed and made into a better person. For him to have to stop that journey for someone, or to find someone so utterly irredeemable he cannot see that path, should shock him to his core. That's how I see this.
The follow up stories examined him wrestling with his decision and that's where that choice really comes from going forward.
It's really not something that needs to come up often but at least it gives the character a basis for his stance rather than just believing killing is inherently wrong, which is a bit harder to reasonably justify when dealing with the abject slavery on Mongul's Hellish Warworld.
The no-kill rule comes from a specific cultural place and is largely a thing because it has always been a thing due to comics being marketed at kids for decades. I think it's fun to explore that with characters, and give them opinions about killing.
I do understand that long-time Superman fans maybe feel it's a story that didn't need to be told. Superman is Superman and Superman doesn't kill. But this was a new Superman being built from the ground up, so a story like this, in his relatively early years, is exactly where you can explore this kind of idea (even if they'd gone with the reverse outcome).
It's a hell of a lot better than New 52 Superman asking his scientific advisor if he is allowed to kill Doomsday (even though they'd fought before so presumably he had done it then and died himself or did he...? It's best not thought about).
Also, Exile is one of my favourite Superman stories and it all starts with the Supergirl Saga.