Should I Write Negative Reviews?

qmarkI have received a book from a publisher for review which I think is poorly written and I really don’t agree with what it tries to teach.

I have a dilema though:

I don’t really like being negative, so what do I do?

Do I post a negative review or do I just discard the book and get on to the next one in the pile?

What would you, my wonderful readers, rather see? No review or a bad one?