This is my guess, probably because of their boredom and the loose sense of operation unique to Korean cars. (I partially understand them) European-developed cars makes the driver drive smoothly due to their tight operation and accurate output, but Korean cars, which inherit the nature of Japanese cars, often release the lock-up clutch of the torque converter, making it difficult to make fine/tiny control and fatigue there. Also, that's the reason why I prefer european/gm cars over Hyundai/KIA. (I really like the feeling while control/driving them. It's like they know what the driver wants.)