Even if you think a space industry is useful in general, there is no reason for humans to be involved. Robots are superior to humans for this application today and will only become more superior in the future.
Gathering more resources so the overlords can have more humans enslaved with shinier golden handcuffs, who can consume more so number line goes up is not a meaningful goal to pursuit, and robotic-only commercially rationalized spaceflight has only this to offer.
Scientific discovery, so we can have better simulations about things of no use or effect on us? Why? Taking people to places and utilizing the resources there, and building a more resilient humanity is a worthy endeavor, and while robots are useful for that, ultimately human spaceflight (or interplanetary/interstellar travel) is he goal, not having only a space industry.
The Jamestown colony relied on shipments from England.
> Building a self-sustaining colony is so far outside the realm of possibility that it isn't worth thinking about
And look at what America became.
Very funny!