If that is the extent of the argument, then I would have to disagree. I'm not sure Rand was knowingly and intentionally "ethically challenged." It seems to me that she thought her philosophy would improve the world. Therefore, I am either on the fence or willing to give her the benefit of the doubt (on a good day) on the matter of her ethics. Apparently, she believed that everyone would benefit in the end if only they subscribed to her philosophy as presented.
However, I agree with Ricter who correctly pointed out the matter of unintended consequences and the fact that Rand evidently did not make allowances for them. The ideal world she envisions is one filled with decent, upstanding citizens. Although she speaks of the virtues of selfishness and so on, you will note that the protagonists in her novel are righteous folk. Unfortunately, there is a sizeable element among us who will interpret Rand's ideals far beyond the scope of her intentions (think WorldCom, Enron, etc., ad infinitum). You need look no further than the cast of characters here at ET to find some people who genuinely but erroneously believe that they are Rand devotees:
http://www.elitetrader.com/vb/showthread.php?s=&threadid=55042&perpage=6&pagenumber=1
Therefore, I think that her philosophy is flawed because, as I noted in an earlier post to this thread, it is not workable in the real world for the same reason that Marx's philosophy would not work. Both premises overlook human nature in one way or another. So I will be a nice guy and conclude that Rand was probably well-intentioned but hopelessly naive. Because there is a sizeable contingent of malevolence in this world, I think that the free reign she proposed would cause us to eventually revert to the laws of the jungle. I doubt that this was her intention.
Consequently, nitro, my conclusion is the exact opposite of yours.