It looks like Darwin was as impressed as everyone else by the amazing ingenuity in orchids and could not ignore the evidence for design.
Darwin was not at all unsure about the value of his orchid book. He viewed it as presenting the most convincing case for natural selection that he could make.
Even Darwin would be aghast at what the world has made of a mere abstract that he was almost pathologically ambivalent about ever publishing.
This stands the standard historiography and received wisdom concerning the development of modern evolutionary theory on its head.
Surely the “iconic” status of Darwin’s book could never have been predicted by either the author or his publisher.