I'm sorry, but what are you even arguing here? That atheists are, in general, fuckwads that would be better behaved if they where religious?
... I'm seriously beginning to doubt whether the inquisition was reinstated. The defensiveness of people is just... Astounding. I'm not interested in making atheists look bad, and I don't think they eat babies. I didn't, when I was one, and I stopped being one for personal reasons, not a dissatisfaction with the "philosophy" itself. Time and again I'm amazed at the viciousness people display in this thread in defending their interpretation of "atheism", as if they're under continuous attack.
I'm arguing that
A. Most people aren't capable of or interested in forming their own morality through game theory as you propose and
B. Your outcome (altruism) isn't necessarily the only outcome of the process you described and
C. Evidence for this is found that people still do "evil" stuff (aka the aforementioned fuckwads, regardless of faith).
and therefore I conclude
D. Evidence-based morality is still something you made up, and even though it might work for you personally, I still think you're bending the concept of "evidence" as you defined it.
I'm not saying that is good, bad, or anything about atheists or theists. I'm just saying that one cannot have morality or values based only on the type of evidence you defined, that you need to just go out on a limb, take a leap of faith, and say "Hey, happiness is a good thing". That is, in itself, a belief not staved by evidence, and is therefore faith, as per the earlier definition.