You're wrong.
I've quoted the civil code of the Republic of Korea, scholarly analysis and case law supporting this right.
If Party A breaches the contract and cannot make amends after a reasonable amount of time then Party B is absolutely allowed to terminate the contract.
This is absolutely not up for debate anymore. It is that easy.
NOW the crux of the matter is whether the reasons that Newjeans gave for termination are legitimate or not. But procedurally everything that Newjeans did was 100% correct.
I'll explain one more time
1. Newjeans sends certified letter of their demands and gives notice of 14 days.
2. Ador does not respond or fix the demands of rectification of the issues within business hours after 14 days.
3. Newjeans then terminates the contract.
Every single step as followed is 100% legal and correct.
What is in question is whether the demands themselves were valid or not.
Newjeans has the legal right to terminate the contract and followed every single step as required to make it valid. They did not cut corners, they did not take shortcuts. Everything done was legally correct.
Here is the but, but were the reasons as stated enough to claim a breach of contract? Well Newjeans thinks so, Ador doesn't. So this is why there is now a court date.