Maps like this seem counterproductive to their cause. If someone's main exposure to the phrase "American occupation" is things like this, and then they visit Seoul and see how great it is, why would they not conclude that "American occupation" is great and they should help more of the world become America-occupied?

Ask any South Korean and they are pretty happy to be on the south side of the 38th parallel. 

Koreans and Americans fought together to create what is now (the miracle of) South Korea.

We shouldn’t downplay their sacrifices

Picture from my hometown of Little Rock Arkansas erected by Korean War veterans