I agree. I've had instances where I was watching a show but couldn't really invest because there wasn't a particular character for me to cling to. So, I could see that being a thing.
To the second point, that is also very much a thing 😭 I'm not familiar with Shining Inheritance but there's definitely an art to writing an antagonist (or protagonist). Whatever feelings you evoke from the viewers—like annoyance, you want so because of the right reasons, not poor/flat writing.
I think I'm just sceptical because some really good shows are being written off because they lack the cookie-cutter "good" guy.
Also, a Han Hyo Joo mention got me excited, but now hearing your review... 🤣