Would you please explain how driving a small car (let's take a Prius as the obvious example) has exactly the same effect on the environment as driving a gas-guzzler? I don't get it.
Because you are comparing apples to apples when in fact you should stop eating apples and eat spinach instead. In relative terms, the Prius vs. Hummer comparison is easy. Prius is considerably better than the Hummer. The problem is that in absolute terms, other than different amount of fuel, both of them require almost the same materials and resources for construction, maintenance, and lifetime operation. Prius drives on the same roads as the Hummer and hence needs the entire highway infrastructure to function properly. Prius uses plastic, metal, and synthetic materials and so does Hummer. Sure, it uses a lot less of each but the factories that produce these compounds still need to be built, serviced, and fueled. The spinach to this apples problem? Better trains and transportation across the entire US such that Walmart no longer needs a fleet of 10,000 trucks.
The big picture is not the comparison between using Prius and Hummer. It is whether automobiles should be the primary mode of long-distance transportation across a nation of 300+ million citizens. The author's point is that the pride from driving a Prius is overshadowing the anger and fury that we all should have at the lack of real, efficient solutions. Prius is a wonderful band-aid but it is not a cure and will never be a cure.
On a personal basis, it is in the best interest for everyone to use fuel-efficient cars, and reduce energy usage. However, this does not mean that doing wonderful "green" things will make more than a minor dent to the real problem of what is actually going on. It is very comforting to use textile bags instead of plastic at the grocery store but it's really not such a big deal in absolute terms. Not having to import every single item from China across the ocean is. The externalities of cheaply manufactured products are borne by China and the world as a whole. The benefit goes only to the shareholders and consumers of Dollar stores. What's the easy fix? There isn't. But using textile bag makes you feel wonderful and proud enough that you no longer think about the big picture and thus have no real voice when it comes to changing the big things.