Why do I enjoy being a local guide? For empathy.
It's very nice of you to have an interest in eating a pizza in one place and to know that there are several comments stating that the place is great for what you want.
I am very thorough and believe that my opinions are judicious assessments and help other people to choose to visit some places or not.
Me, for example, I use a lot Google service because it is a true source of sincere opinion of those people who have visited the place.
in other words Google Local Guide is a public utility service.