I think the "useful as a side effect" comment stems from the fact that the money is being spent to develop things that are primarily for military applications.

I think the "useful as a side effect" comment stems from the fact that the money is being spent to develop things that are primarily for military applications. It just so happens that oftentimes, those applications/technologies can be applied wholly or partially for public uses as well. However, if your end goal is to improve civilian life and infrastructure then development via the military almost certainly isn't the most efficient mechanism to accomplish that goal. That's not to say that military doesn't have its uses, but if public benefit is your main goal then it almost assuredly would be better to create some type of agency or organization that was explicitly tasked and organized in such a way to meet those goals.