When someone reviews a business, the options are; Terrible, Poor, Average, Very good and Excellent.
These options aren't consistently divided up; because there's too big a gap between 'average' and 'very good', and this allows inconsistency to enter the grading system. So, for example, where a customer feels a business is ‘good’ (i.e. better than average, but not very good), they either have bump it up, or (probably more likely) grade it downwards. This is wrong.
There needs to be a ‘good’ option. TripAdvisor has tremendous influence on customer spend, and with that there must surely be tremendous responsibility to ensure businesses are correctly rated (neither lower nor higher than they should be).