This undermines your main argument, because it shows how the military explores territory that would otherwise remain largely unexplored.
When Concorde was on drawing boards, the same tech was re-used and developed further. Supersonic flight turned out to be a dead end, but the control system developed for Concorde (originating from fighter jets) proved valuable and was carried over to later Airbus A300 and Airbus A320 designs, and has given remarkable safety improvements.
While we don't have supersonic flight in 2020, the legacy of early Anglo-French fighter jets and commercially unsuccessful Concorde lives on in every Airbus plane and many other influenced designs.
It’s the second part that is the nut that your argument must crack, and that is a very difficult bar to clear indeed if you in any way value human life.
Don’t believe the hype.
NASA put people on the moon and brought them back. They could design, launch, and operate GPS like they do Hubble and other satellites. It’s well within their expertise. We don’t need to accept DoD funding of violent undertakings that end up killing millions simply for the meager benefits we get as a side effect sometimes.
As a counterexample: the military has had supersonic jets for two generations, and there is no civilian supersonic transport. The only one that did exist was an european undertaking. You get no benefit from any of the billions spent on fast planes by the war machine. None.
Massive defense spending only trickles down to defense contractors. This is just public-to-private wealth transfer, nothing more.