Guy is all over this post commenting nonsense because he's in love with the party that instated martial law recently and tried to do a coup. You're wasting your time on him.
You're completely right that the Korean blues are anything but left. Not even just compared to Corbyn, even compared to European labor parties (the champagne "social democrats" in each country). Biden was more left-wing than the Korean blues. That tells you everything.
In many ways the Korean blues are more nationalist than the reds, which can't be said about basically any modern relevant left-wing party elsewhere. Another good indicator they're absolutely not left-wing.