I dont know why you assume something about korean games, they have a pretty robust gaming market, with RO being one of the most popular/long lasting mmos out there. The company that made that game is pretty highly ranked, NCsoft.
The art direction on the game is also one of the most famous korean artists/designers. It also has been in development for some time, and i dont think its finished yet.
Since its not finished, i also dont know why you have decided its a "grinder"
anyhow i dont know if its related to the engine, it would seem to be a design issue more than anything.