The author assumes that, just because Lewis never published a book, that his information was never used. That he wasn't thoroughly debriefed by Jefferson and his staff upon his return, and his notes used in government planning.
Dont let this guy throw a wet blanket on your reading. We live in a day of revisionist history, and this is a good example. It is good to realize that Lewis and Clark were humans, but it is also good to recognize the amount of courage, tenacity and leadership they must have possessed to keep the expedition together. That is worthy of study.
This is part of the “reconstruction” of the American mythology as an exceptional nation—or as I call it, the “destruction of the American ethose.”
Countries need their myths to teach their citizens that they are bound together by the deeds of past heroes. Where would Rome have been without the stories of their founding by Romulus and Remus and the mother wolf? Did Cincinatus really give up the reins of power when the crises was over? That legend certainly served Rome well in the time of the Consuls and in our own catalogue of civic virtues in America.