Ewwww... This article is out of the gate with a lame assertion. This is like the nutjobs in the crevo discussions who still assert that biology violates thermodynamics. It kind of brings into question the competence of the individual to even be involved in the discussion.
The "Golden Rule", when more rigorously characterized, is mathematically optimal (c.f. "Iterated Prisoner's Dilemma"). Only a fool wouldn't follow the Golden Rule no matter what their religion or lack thereof. The fact that the Golden Rule appears to be universal should be a big clue that it is not a uniquely religious concept (or unique to a particular subset of religions, for that matter).
Other arguments might be interesting, but the assertion that atheists have no reason to live by the Golden Rule is essentially based in ignorance. Trivially falsifiable arguments are pretty distasteful no matter who is making them, and are a net negative.
If I remember the prisoner's delimma correctly, the prisoner who manages to cheat while the other prisoners don't wins more than if everyone cooperates and much more than if everyone cheats. There is no incentive on an individual level to adhere to the golden rule.
http://serendip.brynmawr.edu/playground/pd.html
Most people don't follow it.
The fact that the Golden Rule appears to be universal should be a big clue
Do you know what the Golden Rule is?