The atheism is only a small part of the issue with objectivism. Galt (and thus Rand’s) objection to the concept of original sin is naive, but even absent this aspect of objectivism, it remains a dehumanizing and abhorrent moral philosophy. Rand detests totalitarianism, it is true, but other writers have written better and less repugnant works in defense of capitalism and against totalitarianism. If libertarians and conservatives wish to seek out inspirational works on the topic, they are better off with the likes of George Orwell, C.S. Lewis, Thomas Sowell, Wilhelm Roepke, F.A. Hayek and countless others.See also Maclin Horton (Light on Dark Water) on "Ayn Rand, Crank" and what Ayn Rand got right.
The fundamental problem is that Rand is as naive about human nature as the socialist utopians. After all, a utopian is a utopian, whether they are Marxian or Randian utopians. Therefore the rejection of the concept of original sin is something of a problem because it blinds Rand to the idea that human beings cannot simply shut off their passionate desires. If totalitarians are blind to the reality that human nature cannot be perfected, Rand is blind to the fact that the altruistic tendencies of humans cannot similarly be wiped out. Believe it or not, we are social beings (Aristotle and Aquinas being right), and it is simply unrealistic - and Rand is supposed to be about reason and realism - to expect humans to simply ignore these aspects of their personality.
And of course, Objectivism illustrated: