|Peter Kies Venture-Lieutenant, Illinois—Rockford|
Another way to look at it - the average isn't a great measure of typical value if there aren't a large percentage of responses near the average.
Many of the distributions of review ratings don't have a single clear mode (or two clear modes if responses are split). These distributions more closely approximate a uniform distribution than a unimodal, bimodal or normal distribution.
With more reviews, the most common ratings are likely to emerge, with counts at the peaks that exceed the counts for other rating values by more than just a couple or a handful.
10 reviews was a good cutoff to make sure the report could include a majority of the scenarios, but unless they are all tightly grouped you probably need more like 20 before the distribution of responses has a fairly clear shape. Unfortunately we currently only have a few scenarios that have received 20 or more reviews.