Here is an example of what can happen if a system rewards incorrect actions: Giving bar ratings to make comments visible. The linked post gives examples of people giving one star ratings to make their comment visible. This behavior is not that weird actually if one looks at the motivation of people who write reviews; these people write reviews not to be kind to a developer, but to share their opinion. Their motivation to write the review is to have other people read them. So if the system shows 1 star
comments more than 5 star comments, the way to get other people to read your comment is to give the app a 1 star review.
Good example of the importance of looking at more than just usability when building software and ecosystems.