Yeah I remember reading a long while back about how we supported the oppressive regime in the South, and just thinking "Man, they must hate us." I was pretty surprised to learn that we're viewed pretty favorably, but I guess that probably has more to do with South Korean relations with the North and China more than anything.
Really it's Japan. Compared to them, we're angels in the Korean consciousness. Japan colonized Korea from 1910-1945. During that time the Japanese destroyed/confiscated cultural artifacts and buildings, instituted forced labor (including forced prostitution), and eventually began a policy of cultural assimilation. By contrast the American influence on the peninsula is realtively hands-off or indirect. In my experience there definitely are a lot of people who are discontent with the prescence of US troops in Korea, but there's not the visceral prejudice that many have against Japan. What was surprising to me was that far right-wing nationalists are also typically very pro-American. Which is awkward as I have much more sympathy toward This unfortunately appears to be our country's MO in foreign countries. We have a much lengthier track record of setting up despotisms than democracies.we supported the oppressive regime in the South