Maybe you’ve never been in the situation he was.
He owned his home. Upon selling it, he must tell any prospective buyer that the neighbor upstairs throws feces onto the unit he is trying to sell. That takes a HUGE chunk off the value of your home.
I feel for Mr Kim.
Situations do not determine ethics.
You may not kill everyone who mistreats you.
You do not decide who 'needs' killing.
For a private citizen, killing is pretty much limited to self-defense.
Might I kill someone who harmed my family as an act of retribution? Possibly. But I would do so in the knowledge that I would suffer the penalty of law for my actions.
The analogy which I provided involved a divorce, possibly the least appealing human interaction legally available. Even in an ugly, drawn out divorce, filled with wrong doing and recrimination, painful and unfair, and subject to the divers humiliations inflicted by the justice system - even in this most odious case, going through the legal process is preferable to homicide.
For the record, I have lived long enough to have gone through distasteful situations - worse than having poop on my porch. And I have not killed anyone.