Our society has an absurd tolerance for obscurantists who wish to deny the relevance of the art and science they do not understand. The more obtuse critics of modernism, treated seriously by some journalists, are like creationists (also treated seriously by many journalists and even senators) who attack evolutionary theory because they think Darwin said that we are all descended from monkeys. The message of both groups is a simple celebration of ignorance: what I do not understand is not worth understanding. They may deserve our sympathy, but in the end there is no reason to listen to them. (p. 228)
I suppose Rosen thought he was making a crushing blow against the "obscurantists" here, but to me it seems that he was just showing his own limited understanding. I have no doubt that there are some unsophisticated critics who believe Darwin did say we are all descended from monkeys (it would be more correct to say Darwin posited that humans and monkeys share a common ancestor), but most "creationists" (however broadly one defines the term) offer considerably more sophisticated critiques of Darwin. For example, they may point to the paucity of fossils demonstrating a clear transition from one species to another, or the inability of Darwinian evolution to explain how certain complex structures in biological organisms came about as a result of a step-by-process (the problem of "irreducible complexity"). Whatever one thinks about such arguments, they are certainly not evidence of stupidity.
In fact, I would argue that Rosen would have done well to have refrained from displaying his own ignorance of something he did not really fully understand. He was obviously a very intelligent man, but, unfortunately, like some people who are quite knowledgeable about one subject, he seemed to believe that his expertise in one area qualified him to opine on another. His comments quoted above remind me of Stephen Hawking, the world-famous physicist, who, a number of years ago in his book The Grand Design, asserted that "philosophy is dead," and then went on in the remainder of the book to engage in a considerable amount of philosophizing, without apparently being aware of it (this was ably pointed out by the mathematician John Lennox).
The moral of the story, I suppose, is that we all need to be careful about imagining ourselves to be more knowledgeable about things than we really are. A little bit of humility can go a long way in preventing us from embarrassing ourselves. That said, to be fair to Rosen, he was clearly a gifted writer on those subjects of which he had genuine knowledge, which were many.
Image of Charles Rosen from back-cantantas.com