Basically, the more accurately you rate inns, the higher your reviewer score and it will ultimately lead to a benefit later on in the game. Each inn lists pro's/con's about it and that's how you can decide whether the place deserves a 1, 2, 3, or 4 star rating.
Confusing? Maybe a little at first, but the more inns you rate, the more it will make sense, and the more exciting it is to see what your approval rating gravitates towards with each new inn you encounter.
Try it in the new version!