1) S.Korea, especially Seoul is extermely westernized. It's like being in NYC without anybody understanding English.
2) The notion / ideal of beauty is just a global marketing concept. The most influential and rich nation spreads whatever ideal is pop. For many decades / century it's been Hollywood (maybe European fashion/models/Paris/London too). Bigger eyes make Asian girls look more like global celebrities -> they find their niche and increase desirability -> profit (sorry for my online poker background and business education, but here profit means success or rich husband ).
3) South-Korea is an extremely male-centered, physical apperance oriented society. It's not equal at all between genders, and even many educated women have the sole aim in life to look beautiful. Women are not ashamed to be "just housewives" like in Scandinavia for example they are.
4) It's a common human trait to be interested in exotic qualities and something that you don't have. Either in smaller scale like a blonde girl liking darker haired guys or in a bigger scale as in Asian fancying Westerner or the other way around. Does not matter how "racialist" you are or committed to keeping to your own ethnicity still subconsciously most of us are looking for something different, only the magnitude of the difference varies.
5) Millions of european women would die to look Asian. Cute and girly and the perfect woman of many men.
So ye, in conclusion, it's not that sad.