First a personal admission. Years ago I tried to read Kant to see if I agreed with Rand's conclusion that he was "the most evil man in mankind's history." I didn't get very far! I found his language too obtuse (and my patience way too thin) to get more than a few pages into his Critique of Pure Reason. So I can't attest to the accuracy of Vallicella's interpretation of Kant. Per his profile, Vallicella "taught philosophy at various universities in the USA and abroad before abandoning a tenured position to live the eremitic life of the independent philosopher in the Sonoran desert."
I won't try to summarize Vallicella's analysis here; I recommend reading his post.
While I disagree with Vallicella's harsh labeling Rand as a "hack" I believe he makes some key points about Rand's approach to Kant. My impression is that Rand didn't have the patience (or interest) to digest Kant (and other thinkers). She read enough to get a sense of the thinker's direction. She thought in broad strokes, identifying key principles, but perhaps did not have the temperament to dig into the details of how these principles played out when applied to tough test cases. (I recall an interview with John Hospers in which he pointed out an issue with applying one of her ideas to a real world case that he felt wasn't so clear cut. [I don't remember the issue he brought up.] If my memory is correct, I recall that Rand's response to the point Hospers made was, "You bastard.")the question is not whether Kant's ethical doctrine is true or reasonably maintained; the question is simply whether Rand has fairly presented it. The answer to that is in the negative.So I persist in my view that Rand is a hack, and that this is part of the explanation of why many professional philosophers accord her little respect.That being said, I'll take Rand over a leftist any day.
Rand laid the broad groundwork for her philosophy but didn't write a definitive treatise to define and defend her philosophy in the kind of patient detail that is expected among philosophers.