Of course economics still matters here even for the military, it still will be weighed against conventional satellites and spy planes and so on. But a sales pitch of:
>"We can pick up your bird from anywhere with enough runway, fly it to somewhere it can be launched at any time with minimal to zero worries about weather, other air traffic, or bothering (or even being visible to) populated areas, and hit any azimuth (no population overflight concerns either)"
seems like it might be worth something at least. It's certainly somewhat different beyond cost at least, even if it doesn't matter to most. The AF has their own robotic spaceplane project after all, seems like there is at least some interest in this kind of area?
If this does come to fruit in real life, it wouldn't be the first time that ideas from his books have become reality 10-20 years later.
I don’t know a whole lot about spy satellites, but the existence of things like spy planes and accurate ICBMs suggests the latter.
I don't know if ultimately there is a big enough market but I can at least see theoretical potential there, and just in general it often works better to try to carve out a specialized niche with higher margins then take the 400kg gorillas head-on at their greatest strengths. And if the medium/medium-heavy launchers work then this doesn't have a total joke payload either, 3.4 to 6 tons to LEO isn't just cubesats.
It'll be interesting to see how it goes at any rate whether it pans out or not. It's ambitious and it could offer a niche but new additional mission capability.