[newheart]

Many people act as if atheism has no fallout whatsoever.

I agree. for me, the real problem with Rand's approach and with any system that does not allow for an objective basis for good and bad, is that eventually pure selfishness inexorably creeps in. It becomes very subjective (real irony in the name "objectivism") and devolves into the only real values are my own. It is closer to Nietszche than Christianity and as Nietszche saw clearly, power is all that sustains and enforces self-driven systems. If you have the power, you rule. And if you don't have the power, you are the ruled.

[NYCslicker]

“If you have the power, you rule. And if you don’t have the power, you are the ruled.”

That’s just a statement of fact, not a statement of fact according to Rand, but a statement of the world as it is, the “metaphysically given.”

[He Rides A White Horse]

I agree. for me, the real problem with Rand's approach and with any system that does not allow for an objective basis for good and bad, is that eventually pure selfishness inexorably creeps in. It becomes very subjective (real irony in the name "objectivism") and devolves into the only real values are my own.

Emphasis mine. That is the crux of the matter. It is ironic as you state with respect to an objectivity devolving into subjectivity. Since we are all human beings, by our very nature we will have morals, morals of great difference ranging to similarity. It is a basic human condition, and cannot be ignored.