People who have watched the original one before the remake are hating this remake a lot. I know original is original but it does not mean this Korean remake is bad.

The reason people hate remake who have watched the original one is because they are already attached to the original film/series. And when they watch the remake they just cannot get used to the new cast and new angles of the film/series. They just cannot imagine the same story and character with different actor than the ones in the original film/series.

it's like if you watch a remake of Iron Man with different actor after watching the original one which has Robert Downey Jr in it, you will definitely dislike it. But if you happened to have never watched the original Iron Man movie then you might like the remake one.

Now if I watch the original drama, I will definitely like the remake version more than the original one, because I watched the remake one first.

What I am trying to say is, both the original and the remake are very good. Because it's the same drama with different languages and actors.