I do wonder if Rand was a sort of an evangelist in a sense for a more reasoned-out philosophy than what existed and maybe she thought something like, "Okay, this is good enough for now--now I'm going to go out and spread the word of this particular philosophy." Certainty does have a certain rhetorical use, and if it persuades people away form a less reasonable approach, maybe it's worthwhile. If we all sat around waiting for perfect knowledge before we started talking about our ideas, we'd never speak.

Not to say I necessarily endorse Rand's approach--my impression is she was too rigid, but at the same time, did she do a service for advancing better ideas than the average to the general public? I think a decent case could be made for her on that count.