I recently used Uber (an online service for ordering a car and driver) and did not have the usual pleasant experience.
The driver did not know the area, and, worse, he did not follow his navigator's instructions, turning left instead of right. When Uber asked me, as usual, to rate the driver, I did not hesitate to give him 2 out of 5. I was not being vindictive; I wanted to save other passengers from an unpleasant experience, and I hoped that maybe feedback would encourage him to improve or find another line of work.
But what does 2 out of 5 mean? It obviously means worse than average, which would be 3. But, while I would always pick an average driver over a driver with a rating of 2, given the choice between a 2-driver and a blind pick, I might pick the 2, because the fear of someone even worse would keep me from taking a risk.