Some people in the comments are attempting to defend Bum Seok because he only has a trauma; the others have trauma as well, especially Youngyi, who has the biggest trauma, but they are not backstabbers; you can say he is a well-written character, but he is not right; everything about him is wrong; he is not the grey character that y'all are discussing.
I can't believe they wasted Juhee's potential by making her just an annoying character; she should have been written as a more complex character rather than a cartoon. Taeyong is the same way; even with their backstories, they are cartoonish. The author made a huge mistake.