I like reviewers and I like readers.
So I strongly agree with this post:
"Book bloggers don't owe you anything. Their blogs are theirs and they can blog about whatever the hell they want. This is not a job."
I support book bloggers in their thoughtful work, and I am very opposed to any authors ever taking offense at a review. That's not an author's place, and demonstrates remarkable immaturity.
Book bloggers are fundamentally "readers who care" -- and I love to have active, engaged readers -- even if (and especially if) they are finding weaknesses and focused on improving books! Yay for book bloggers!