Ji-N3:
I think you’ve already answered your own question. People who like the drama are usually more vocal and leave positive comments. However, those who don’t like it often don’t comment but still leave a rating. That’s likely why the overall rating is going down even though the comments are positive.
No, I still haven't received my answer. Because despite high ratings being given for a series for days, the overall score is not increasing. And this has happened with many dramas. So, do the scores change according to the votes given by the viewers?