I think it's interesting to note that North Korea was supposed to be a character, but for some reason taken out. Good choice. If the fans out there thought South Korea "over reacted," they don't want to know how North Korea would react. They would be something much worse rather than just demand a character taken out from the show. In the Korean news broadcast I saw apparently North Korea find Hetalia hilarious only because it makes fun of the countries around the world and South Korea! If the show made fun North Korea, they said they would retaliate. If you get their hint.
Also I debated with a Hetalia fan about why Korea banned only and I repeat only the character from the show. She replied saying that Korea over reacted and that they are so insulted, Korea should just make a show making fun of Japan. In fact we did. BUT Japan threatened Korea that if the show / comic book went outside of Asia. Japan would sue the country of Korea. (Hmm sound familiar?) Korea stops publishing / airing the show completely in a matter of days.
Now Japan comes around and makes a manga / show making fun of Korea and when Korea tells Japan that they don't like what they are doing. Korea gets blamed and ridiculed and the Japanese author is allowed to publish his work? I'm sorry why is it ok for Japan to publish a manga/ tv show that slanders Korea, but when Korea publishes a comic / tv show making fun of Japan; it's a major no?!