Excellent post! Nailed it exactly.
The left hates religion, so Rand’s elimination of it makes her novels/concepts/ideals the perfect weapon against them. For example, I’m arguing with some pro-infanticide lefty on our local newspaper’s website. She keeps accusing me of throwing my religion around yet I have not used religion to prove why infanticide is wrong. She now has no argument because she fully intended to use that as her only argument. It really pi$$es the left off when you take religion out of an argument because then they can’t whine about it and change the argument to a religious debate.