An Unwanted Guest discussion

When writng opinions for any book, I wish people would not start writing what the book is about; that's already been done when you look at the main page for any book. I'll never understand why anyone wants to repeat this process. Just write what you think and not repeat the overview/synopsis or whatever it's called. So annoying. We just want to read what you think, we already know what the book is about. All that wasted writing and space and it makes it hard to find the opinion itself.
FYI where it says "Book this topic is about" I can't put 'all books' it won't allow it, because I do mean all books not just one, so I just selected the last book I read.