Mr. Aboulafia
I agree in part re: Concorde, Comet. Overambitious expectations with extrapolated technology. The Concorde was never "practical"; it was sold that way. The Comet failed with outdated technology and an unfounded belief in luck.
A proven platform is the best "gamble", until one exceeds practical limits. (A380) Hard to keep 600pax waiting between "flights". "Friction-Stir" welding- Eclipse.
Romance enough in breaking ground and making money. Did that. You must read BOYD by Robert Coram. The father of the F-15 and -16. He broke the Pentagon's back, and made McNamara the fool (not difficult). Enjoyed your essay immensely.
AF