South Korea has given up on talking to the North

The South's current government is ridiculously conservative. Rolling back labour laws and women's rights were pillars of their election run. They'll do whatever the US tells them to. It shouldn't come as a surprise that peaceful diplomacy is not at the forefront of their mind.

It's honestly pretty cyclical, they bounce back and forth between more diplomatic minded leadership and more warhungry. They are much more in the antagonistic phase of their cycle right now.