I addressed this in a different comment, but the distinction is one of immediacy of existential threat. The DoD funding is framed in this context (and 60 years ago, NASA's as well - when it was almost 10x the fraction of GDP that it is today).

If people think there is an existential threat to their way of life, it's hard to convince them to take from that pocket to fund something more fanciful and likely only relevant generations away (if ever). That's the insidious part of the military boogeyman...and SpaceX probably knows this as well since they garner defense contracts too.