You know, I remember reading this book when I was a teenager. I don't remember getting any negative ideas about RPGs though. I just read it as a horror/suspense book.
I might get something different from it if I read it again.
By the way, I still play RPGs and its been probably 15 years since I read this book.
My memory of the book would give it 4 stars but I'll give it 3 since I wouldn't be willing to read it again.