I dated a Korean who grew up in one of those Seoul suburbs (newer and nicer than the drab ones in the photos, but similarly composed of skyscrapers), which I also visited myself. She loves it and prefers it there. It's extremely convenient. Everything is walkable - restaurants, parks, stores, etc. You don't need a car, and mass transit is fantastic. 20-30 minutes by subway to Gangnam (14 miles away) for 3000 won ($2.65).
I grew up in the American suburbs and now live in Manhattan. I hate American suburbs with a passion. Inconvenient, car-dependent, and isolating. NYC is great, but the apartments here are old and terrible by modern standards (not to mention the decrepit subway).
The problem is that America seems to care more about aesthetic appearance than actual living conditions. I don't think anyone will disagree with you that those Soviet-style blocks of identical apartments are ugly from the outside, but I'd rather live in a modern high-rise than some shitty 100 year old 5 story tenement walkup, or some giant house in the suburbs where I can't get anywhere without a car.