It might just be one. Or ten. We know that everybody is entitled to his or her opinion. And as my husband says, "Opinions are like belly buttons, everybody has one and everybody's is different." (He also equates opinions with other body parts, but like my novels, this is a G-rated post, so I will refrain.)
When a woman wrote that she felt like goauging her eyes out while reading my debut novel, Rain Song, I must confess I was a bit bothered. As a new author, I hadn't expected such venom from another human. Then I ended up laughing as I tried to imagine what goauging eyes out looked like. Not finding a definition for goauging in any of my dictionaries, I thought that perhaps she had meant to write gouging. Gouging is a metal tool with a curved, sharp end that is used to cut and shape wood. Had that been what she felt like doing while reading my novel?
A bit gothic for this G-rated inspirational author to stomach.

Since Rain Song's debut at six years later, I still get unhappy reviews. Truthfully, I don't even read reviews for my novels anymore. In fact, I encourage new authors not to read the reviews for their books either.
You can get so bogged down in the poor reviews, you might feel like cow manure and never be able to lift a finger to write again.
That's not good.
However, I will let myself indulge in the reviews fellow authors receive. I have found some well-written unfavorable reviews on books I have enjoyed and some lengthy prose on books I wasn't as fond of, but the reviews were written with attention to detail and contained points that were thought-provoking. (To see examples of these, go to the Amazon page for The Help and look at some of those 2-star reviews.) I have also seen some poorly-written reviews for The Help as well as for lesser-known works.
Which brings me to, if you're going to write a bad review, can you at least do a little spell checking before letting it run wild and live on Amazon?
After writing a happy 5-star review for a book on journaling, I read a 2-star review for the same book. Sadly, the reviewer ended his review with, "Sorry to be such a "bad sport" about this book, but I just didn't find it worth whiled." Hmmm . . . I wonder if any book is worth whiled?
So let your voice be heard! Everybody needs an opinion! But if you are going to write a book review, particularly one that is negative, make sure you've gone over your grammar notes first.
Otherwise, you sound pretty silly.