Apparently it was good enough to...

Well, I haven't watched this movie to actually comment something...
But, I think the film's very low rating is due to the raters perception that the US was unfairly portraited in this movie.
Again, I haven't seen this movie to actually comment...
But, I know the historic event and the US was def. involved in this atrocity unlike what the reviewers of this film here hope to believe.

Korea was annexed by Japan in 1910 and liberated from them in 1945 by the US and the Soviets. Northern part was liberated by the Soviets and later became the communist North while the South was done by the US.
What many outside of Korea don't know is that from 1945 to 1948, Southern Korea was ruled by the American military forces who came to liberate.
They think the US army came to Korea first after the start of the Korean war but that's just flat out wrong.

The event from the movie happened during the tail end of that American rule. So denying the role of the US in this unfortunate event is just ignorant.

At the time, the Americans were preparing for the first ever democratic election in the South. And before handing over the reign to the new infant South Korean government, the US wanted to clean off all the communist elements in the south.

I think what the US wanted ultimately was the South to build strong democracy against the communist North.
It's just unfortunate that some innocent people like the ones in this event had to lose their lives for that.