Writing only positive reviews is like living in a total state of denial. Authors know what they are exposed to when they publish their work. If authors only want to hear praise and glory about their work, how would they know how to get better in their craft? There is always room for improvement in anything.
If Authors don’t like getting negative reviews, it’s their problem. People need to be able to get everything, the good and the bad, in order to make their own opinions about things, in this case books.
I like reading both sides of the story. Sometimes the bad reviews have avoided me losing time reading things I know I won’t enjoy. But there have been other times when the bad reviews have not impeded me from reading a book that I actually enjoyed.
Human beings have the right to express their opinions freely and respectfully. No one should take that away from us.