Authors all want to gather positive reviews, not only because they’re encouraging and feed your ego, but because they help readers decide if they’ll like it and then, hopefully, buy it. Being an active reviewer yourself is good karma and helps you network with others.
You can learn a lot about writing from other author’s work, both negative and positive. Once in a while something in a book may drive you to distraction. When this happens, think long and hard about whether you’ve ever been guilty of the same faux pas. When you read something that makes you hope you can write that well someday, spend some time analyzing what made it so outstanding so you can incorporate a similar technique in your work.