Hmmm... interesting. Let's go through this...
If South Korea had attacked North Korea by crossing the border at multiple locations, killing thousands of NK's in ambushes and taking a couple thousand or so NK's back to SK as hostages for protection/negotiation. I would certainly expect NK to retaliate. They rightly should.
Anyone, and I mean ANYONE, who thinks NK wouldn't or shouldn't retaliate needs their head examined.
If NK retaliates with zeal - that should not be judged by outsiders. This is a personal conflict between countries with a deep past. In fighting fire with fire, things will very likely get out of hand one way or another. This was the gamble SK took to begin with - there was no guarantee they would be successful, or that a counter offensive wouldn't be swift and merciless.
Now here we sit. NK's counter was swift, merciless, and even more powerful than anyone expected.
SK still has the hostages they've kidnapped and continue to refuse to release them - even though the position they've chosen leaves them with the people of their country starving to death.
Can the starvation be ended - yes, to at least some degree, by releasing the hostages.
Can the conflict be ended - yes, to at least some degree, by releasing the hostages.
But the conflict still continues? - yes, because SK refuses to release the hostages.
If SK were to release all the hostages? - that would be a step toward the resolution and end of the conflict.
I'm unconvinced that if NK had done something like this, that it would be any different than it is right now.
The "atrocity" is far more about what was done on 10/7 and the currently unreleased hostages than the response to both these things.
The response was swift, powerful, merciless, and unending.
If I were a hostage, that is exactly what I would want. If I were a hostage's family member, it is exactly what I would demand. If I were either, I'd expect nothing less.