The brilliant Roderick Long put his finger on it in his blogpost A View to a Kill: he crystallized what I have long sensed about Rand but had been unable to put into words: that one of her flaws, one trait that helps explain some of her ill-thought-out views, is her impatience. Notes Long:

In general Rand tended to be rather cavalier with questions of casuistry (the application of moral principles to hard cases) – a symptom, perhaps, of what I’ve long considered her chief philosophical failing: impatience. Elsewhere in the Q & A book she notes that “if there’s one thing I cannot do mentally, it’s handle anything more than two ‘ifs’” (p. 170) – as though this were a feature, not a bug. In fact she’s quite mistaken; in plotting a novel she could be enormously painstaking and patient in constructing a complex and detailed structure and making sure every bit of it fit; that’s because, as I believe, she loved writing fiction far more than she loved writing nonfiction, taking up the latter primarily as a theoretical biologist might decide to act as a medic during a plague. That, I hypothesise, is why she had so much less patience for detail in her nonfiction than in her fiction (I’ve written more about this here), which, I further hypothesize, helps to explain why she tended to allow herself (I don’t mean consciously) to answer these sorts of questions on the basis of gut feeling rather than a consistent philosophical analysis.

Brilliant analysis, though I think his explanation for why she was impatient may be a bit incomplete. I suspect it had something to do with her being a woman, a religious and political minority, an immigrant, very smart, and the beginnings of the almost cult-like following that started to spring up around her–it was her reaction to it (in part). It suggests also why she felt compelled to turn even her own personal preferences and tastes–cigarettes, music, capes–into moral absolutes, rather than just realizing it was her own thing, but not necessarily others’.

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