You are right, what is she talking about? 7.5 is too freaking generous. Take on a case, make scene on site, solve…
There's different types of k dramas. Some, like this one, have episodic narratives. It's normal and valid. Not every single genre has to have a different narrative every single episode. For what the k drama offers, it's pretty good. You have to think on the genre of the k drama before rating. That's what I do.