Liu Cixin himself was quoted that he couldn't start the narrative as straight up science fiction because this genre is essentially unknowm in China. So he decided to build up to the actual science fiction part of the story in a deliberate, slow pace. The story arc then develops from an almost historic setting with Rwd Coast Base as a starting point to some crazy ending to the arc that is way out there at the end of book three.

Every serious critique of the books that I came across mentions the poor character portrayals. But the story offers a view of a universe that is intrinsically hostile in a very depressing way and I did enjoy it for that.