I remember I liked the characters who understood that a technical understanding of an issue screens off vaguer impressions (like with whether Rearden Metal was safe or not), I liked the individualism, and the idea that you don't have to feel guilty about every obligation which others would like to saddle you with just by their expectations... there were other things, but hard to list right now.

As to the quote, well, I can't speak for the whole community, but here's why I didn't like it. Maybe Rand is referering to a specific situation where she knows Branden's thought processes and her statements are correct. In that case, I wouldn't know. But if it's meant generally enough to be a rationality quote - if it's meant to explain why we get angry at dishonest people - then it's just an unsupported claim. I don't see anything showing that Rand has a model-with-moving-parts understanding of the psychology of anger response, and didn't just make up an answer that fit her preferred moral categories.

And equating dishonesty with both evil AND irrationality rubs me wrong. Rand believed that she's basically solved morality, and rationality only allowed one kind of morality, namely hers. Not just metamorality, but specific values. I believe this is part of what locked her into an inescapable worldview, beyond correction and updating (like what Branden wrote about how, once she decided that Reason's verdict on hypnosis was that it was bunk and had no foundation in reality, nothing could reach her on the subject), because once she decided something was incorrect, it was not just incorrect, but Evil.

I think it more useful to consider rationality (correct reading of reality and decision making) separately from values held.