They don't operate in Korea but they do provide Korean translations which seems to suggest they consider inbound tourists as a target market. It is quite telling the Korean apps do not.
Uber attempted to operate in Korea and failed. At that point keeping a Korean translation would have been a simple matter of maintaining and updating it for the small returns that it brought in, coupled with the knowledge that simply maintaining a Korean translation for their vastly more entrenched service ensured no chance of competition from one of the few non-American firms to succeed in the same space as them.