“Every gun that is made, every warship launched, every rocket fired signifies in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed. This world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children. This is not a way of life at all in any true sense. Under the clouds of war, it is humanity hanging on a cross of iron.” ― Dwight D. Eisenhower

I agree, the argument is silly on it's face, but pragmatically speaking, until we can "convince"[0][1] every person alive (and the empowered leaders) to find other ways to allocate resources more efficiently such that everyone is satisfied to the degree of their own ideal resource consumption without resorting to conflict, I doubt things will change.

Besides, def establishment is already clamoring for a "why not both option"[2] with increasing the development of capabilities to conduct war in space.

[0] I have some ideas about how this can be done in practice in the future, though I suspect some could call it the War on Humans™

[1] https://elifesciences.org/articles/27069 "Tetherless magnetothermal deep brain neuro-stimulation"

[2] http://spacenews.com/air-force-chief-goldfein-well-be-fighti...

"Necessity is the mother of invention". If you don't desperately need something, you don't need to put resources into developing it. Unfortunately, war has driven technological progress. And that also includes the space programme. If the cold war hadn't driven the space race, then I suspect space exploration would be a distant and poorly-funded priority.

Without a sufficiently good reason, governments won't put money directly into research (at least, in the eye-wateringly large quantities spent in wartime).

Practically speaking, the money would never be allocated without a good reason. War is a reason to do things. People don't buy into other reasons as strongly as "that guy over there is trying to kill you."