nobody equated china to north korea. the post you are replying to applied equivalent logic to an extreme example (north korea) to show more easily that the logic cannot be correct.
An extreme example changes the logic here, which basically means it's a bad example. And if we're talking about the logic of this argument, there's no such thing as morality in foreign relations. I don't see any morality when everyone buys oil from Saudi Arabia or Qatar, knowing how they treat their own citizens and who they sponsor.
States use the "morality" argument when they need to build a narrative and portray someone as bad/evil to justify actions against them, while the real reason is almost always geopolitical interests or money/resources.
