This topic is always very touchy as each person has their own view on what is good and bad. Negative Reviews are part of this topic as well.
Negative Reviews can be seen as an attack. This is not necessarily the case but what I call negative is a review that doesn’t accentuate any positive parts of a book. Let me be frank I dislike these types of reviews because it doesn’t always show a real feel for the book. Reviews like this also might attack an author or the readers who liked this book.
A bad review is one that is critical giving reasons why the person didn’t enjoy the book but will give both good and bad points. These reviews are common and while you may not like them they are meant to improve the author as well as inform potential readers.
A good review for me is one thst is mostly positives and that has few faults. This isn’t to say it’s perfect but nothing major stands out that makes enjoyment any less.
For my blog I always want to just post good reviews as its a blog about my love of books and reading. I will not post bad reviews on my blog nor negative reviews. This is just my take on it as I want to support authors and help readers fins their next book.