A lot of people probably like unnecessarily dramatic storylines. I love crime and detective drama with a bit of comedy and romance and this drama finds a way to combine all 3 without doing too much.
Most dramas are unnecessarily long, filled with events that do not sometimes make sense. This drama makes good use of its length, little filler scenes.
I want to believe the rating will increase because this drama is better than a lot of popular dramas. People complain of cliches but they rate dramas with cliches higher for some reason.