Feedback, aka reviews, is essential to an author for a multitude of reasons. When I first started writing one of my very first reviews was constructive criticism with a supportive conclusion. Reviewers can and should give criticism, but they don’t have to be hateful and dismissive to get their point across. If there was something that didn’t make sense, let the author know just as you should let them know if you loved the book and want to read more on the characters. My last review on Didn’t See That Coming wants more and that kind of encouragement is all I need to continue the series.
I use feedback to assess what the reader wants to read, so talk to me, tell me what you think. Your opinions matter to this author.