Probably the logic of the ruling party: this president is not great, but if we impeach him now there will be elections and a new president will be elected, this time one from the opposition party. Competent president working for the other party might be considered worse than an incompetent and corrupt one.
I am sure they would vote for impeachment if they had real chances of winning the presidential elections.
Disclaimer: I know nothing about Korean politics, except some recent headlines.
Because its more complicated than him just being a bad guy.
He did a stupid, very bad move, but it was because the CCP-infected, anti-Japan opposition passed a budget that forced his hand, it would have apparently cut all government funding by a ridiculous degree.
That budget cut was 0.7%. I have no sympathy. I will not be surprised when it comes out that this guy is in a cult and his cult leader got their shit cut and this unhinged response was the result.
For better context, here's what was going on with the budget., including the opposition party stopping aid to Ukraine and fighting investments that would make South Korea less reliant on Chinese semiconductors.
At 0.7 percentage points off a 3.2 point increase it's absolutely not what Yoon is characterizing it as and Bloomberg is giving Yoon and his ministers space rent free in that article.