This is what Quinn has said if we look at the fundamentals; that God (of Abraham, Isaac and Jacob) has led the people of the world into destroying the environment. While the gods that the primitives worshipped, while not being benevolent (if you have read The Holy you know what I mean), they at least knew how to not destroy the environment. The reader is left with the impression that it is more "environmentally friendly" to follow the false gods, rather than the living God.

Looked at like this it is incredible that anyone could believe that one should worship something that is false! But Quinn interprets "false" to mean simply not the living God, but other gods - just as real as you or me. But lets look at what scripture says.

Ps 4:2

"How long, O men, will you turn my glory into shame? How long will you love delusions and seek false gods?"

Jer 16:19

"Our fathers possessed nothing but false gods, worthless idols that did them no good."

Ps 40:4

"Blessed is the man who makes the LORD his trust, who does not look to the proud, to those who turn aside to false gods." 

Read also Isaiah chapter 44 about idols and false gods.

From this we can plainly gather that the false gods are false simply because they arent real. They are figments of the imagination of men and nothing else. Deluded men gets an idea in their mind that something is telling them what to do and they turn this feeling into an image, like a carved piece of wood or stone or similar and then they worship it. Does that make things a reality? Ofcource the answer is no. The facts remain wether men knows or understand the facts or not. The pull of gravity exists regardless of the opinions of men!

Remember that Quinn proposed that his worldview is irreconcilable with the Christian worldview, he said that he could not find any way to reconcile them. If there were anyone who could do it he didnt know how they could. Remember also that Quinns entire project, his entire theory rests upon the idea that mankind has been led astray by a cultural belief, and that this cultural belief comes from monotheism. In one paragraph Quinn says that people are becomes self righteous and "haughty" when they believe in the One true God. 

In "Ishmael" this is further underscored with the story of the primitives who are told they are "ignorant" and the, I presume westerner, scoffs at their idols who cant help them.

But when we read the Bible we see that this is not matter of who is more righteous than someone else, its simply a matter of facts. False gods/idols cant help man because they are idle emptiness, they arent real. Its like worshipping a stone or a puppet or a toad. We may wonder at why someone would worship a carved image and think that there would be anything to gain from it. But since Quinn has painted an image of the environmentally friendly primitive who worship such things, many readers might come to think that primitives has somekind of 'special' or 'secret' knowledge. Every person in the world has a religious longing, this includes primitives as well as those living in the civilization. This religious longing takes various forms of expression, and if there is nothing that can guide the thought it can lead practically anywhere. Including into worshipping idols or worshipping oneself like in new age or becoming a hedonist, believing that seeking pleasure is the answer to this longing, or that a sustainable environment will finally satisfy it. But it wont, because thats an impossibility. not because the environment cant be saved, but because a saved environment will not satisfy the longing anymore than a big bank account, a flashy car, access to the ocean or the forest will.