I take issue with this statement, but I'm sure you'll find my point of contention trivial or one of semantics. Not believing in a God or gods is the default position of all human beings. You, me and even the Pope were born as atheists or "lacking the belief in a God or gods." I'm not saying that we were born with the actual belief that a God or gods do not exist, but we certainly lacked the belief. Does a new born infant believe in Santa Claus? Of course not. They are introduced to this myth at a time when they are old enough to grasp it, but not too old so as to know to reject it as irrational.
The same applies to the God concept. It is only when the God concept is introduced that people have a choice to make, namely, whether or not to believe in a God or gods. Typically, the myth of a deity is introduced when a person is in their youth - their brains are young, naive and impressionable. Belief is not an option at this developmental stage.
So I would argue that, in most cases, faith is not an option, but a byproduct of brainwashing. And brainwashing is abuse. Brainwashing a child is child abuse. Oh, I am dead serious.
But a rejection of the God hypothesis is not a "decision" any more than it is a decision to believe that the Earth is spherical. Using the word "decision" implies that the atheist makes a conscious choice between believing and not believing. Rejecting the God concept was not a choice for even a single atheist I know. We rejected the myth of God because the evidence is so lacking that belief wouldn't make sense.
I'm an agnostic atheist and I find great value in this book. Understanding how and why people believe what they believe is important to me as I really think this is the first step in helping these same people get rid of the crutch of faith. You cannot help a delusional person if you don't understand the nature and cause of their delusions. If all atheists wanted to do was roll up in a ball and live a solitary existence as if they are not an integral part of a greater social group than I can see the futility on reading and learning about how delusional people think and believe. But I am influenced daily by the thoughts, beliefs and subsequent actions of the faithful. I want to understand how they tick.
Sometimes authors write books because they think they have a new way of introducing subject material. Guy Harrison does a fantastic job of stepping through the reasons people give for believing in a god -- better than anyone I have ever seen before. I see value in this book. He is direct and to the point using no unneeded philosophical fluff.