answer: because businesses pay for customer reviews.
there are other ways that businesses put their fingers on the scale:
- when owners rate their own business
- when the owners' relatives and friends rate their business
- when the owner's employees rate their employer
- when owners offer incentives to employees for good reviews
so,
- should the minimum score on a customer rating be 1 star?
- should owners or their relatives or employees be allowed to put their fingers on the scale?