I'll just clarify one misconception: it's not really the case that iPhone is considered an international symbol of prestige and luxury. While they are expensive, they aren't that expensive, compared to Samsung phones. Anyone who can afford a top-line Samsung phone can easily afford an iPhone.

In addition, South Korea's dreadful web ecosystem (you can't buy anything using Mac OS) has the effect of substantially reducing the appeal of Apple products. IMHO, using Apple products in Korea is more viewed as being "that weird guy who is being different just for the sake of being different" rather than having an "international symbol of prestige," whatever that means. (Of course both are exaggeration: people don't really care that much what kind phone you use.)

Also there's the matter of Apple's customer service: for some reason they have a reputation of being absolutely horrible in Korea, which leads to fewer sales, which again makes Apple think it's not worth the trouble to set up decent customer service in Korea...

* About Samsung being Korea's national icon.... haha serves me right for not fighting hard enough to throw its leaders into jail, I guess.