Sometimes the reviews also don't match the rating. I see this happen all the time, not only on Amazon:
"Great service, great product. No complaints." 1 star
I confronted someone who left this sort of my review on my mobile app to ask why they gave me one star if they were so pleased. It was the only review under five stars.
They said that they wanted their review to appear in the "top negative review" column since it didn't have a shot at the "top positive review" column.
I noticed my ex-girlfriend rating our Uber driver 3/5 stars once we arrived at the airport. I asked her what was wrong with him. She said he was fine but it was just an average ride, nothing exceptional. And that she's only given out one 4/5 and zero 5/5's.
Not her fault. What choice do you have but to assign your own arbitrary meanings to each star, and how aren't those going to vary from person to person?
I agree it's frustrating that most sites leave it up to each individual user to decide what each star rating means.
On the other hand, I don't think it's really a problem as long as users are consistent. It doesn't matter how "harsh" they are as long as everyone has similar odds of getting a harsh reviewer.
I do tend to leave slightly below-average ratings because I like leaving room for truly exceptional products/experiences to get a higher rating.
I used to see this very commonly on a site with a dropdown rating system. I believe people were selecting 5 stars and then trying to scroll down the page. Since they'd be focused on the dropdown it'd change their rating to 1 star. That was my hypothesis anyway.
They said that they wanted their review to appear in the "top negative review" column since it didn't have a shot at the "top positive review" column.
I was dumbfounded.