I would argue that it was not a "blind spot." Instead, I suspect that Rand's atheism was actually the starting point of her philosophy, as opposed to being a logical consequence of it. She may well have wanted to find some way of justifying the last 6 Commandments without having to deal with the unpleasant (to her) implications of the first four.
You can see hints of this if you take seriously the basic premises of Rand's philosophy. They really don't hold up to sustained analysis; at the very least, they don't hold up as "objective" premises. In fact, in many respects they're not even consistent among themselves. And her "highest moral purpose" -- pursuit of happiness -- isn't even an objective concept.
Her biggest error -- and it's clearly an error -- is to suggest that "man -- every man -- is an end in himself," represents an objectively true statement. Just to pick one among several objections to this, reference to the real world (in accordance with Rand's own demands) suggests that we are much more plausibly characterized as a means to our children's ends.
A charitable person might suggest that the childless Rand never grasped the implications of being a parent. OTOH, given the fact that Rand was a rather ardent supporter of abortion, it would seem that she understood full well the implications of parenthood and, in typical fashion, she simply blasted past the problem, hoping nobody would notice.
Note that we need not even invoke God to see that Rand's philosophy is built on sand. Acknowledgement of God's existence only makes the collapse more spectacular.
This is all pretty obvious stuff -- certainly not something that could easily be missed by a person who accorded such weight to reason and logic. I've concluded that her philosophy was rooted in a) her own towering ego; and b) a childishly emotional opposition to the One who posed the greatest threat to it.
Perhaps you recall the little anecdote from Atlas Shrugged, when the toddler Dagny Taggart threw such a fit in church that they never took her back. This was almost certainly Rand expressing her own essentially child-like reaction to the implications of God and His Church.
Great catch, r9etb! I'd forgotten about that particular episode. But I do recall that I found Dagny a thoroughly repugnant character throughout the book, and was well aware at the time that she was merely the projection of Ayn Rand's self-glorified ego.
Sigh. I agree with you that Ayn Rand started out to prove that her atheist philosophy was tenable. Alas, not only did she never prove that at all, but rather (inadvertently) showed that atheism is fundamentally irrational.
At least that was my takeaway from Atlas Shrugged. Go figure.
Thank you ever so much, r9etb, for your deeply perceptive and well-analyzed commentary.