This may be related to differences in social norms and the fast-paced daily life in Korea, so it is something worth keeping in mind as a visitor.
Transportation is definitely related to the culture here. Korea went through a lot after Japanese colonization. However, within the last 40 years, it has transformed from a poor and struggling country into a modernized and developing nation that attracts many tourists every year. Accordingly, Korea has managed to keep up with these changes and adapt to them, including in its transportation system. Also, thanks to its strong public transportation network, people in Seoul have less need to rely on cars, which I would consider to be aligned with the country’s environmental concerns.
