Well, replace with borderline spacefaring if you prefer. On the timeframes people are throwing around here, neither the "borderline" nor our previous false start, or not even a few more false starts in our future make any difference.

It's still incredibly optimistic. It may very well remain the domain of only a precious few career experts for quite some time, if not indefinitely, unless space begins to generate absurd revenue unavailable on Earth. There are valid and practical reasons for LEO. Beyond that, the Moon, Mars, Asteroid Belt, moons of Jupiter, etc., I don't see any advantage other than discovery and the benefit of working out how to do something (but not how to do something cheaply). Somehow ferrying back a massive asteroid made of pure gold matching the amount already on Earth would likely not even be profitable.

I suppose that climbing Everest never had any practical purpose, and an economy has developed around it. But still, cost per person is a fraction of $1M to do so. It costs an average of $58M/person to get to orbit and back safely for a short trip, and that is just LEO for a few days or maybe a couple weeks. Economies of scale may never materialize for space travel. Even if we do legitimately become spacefaring and stretch out into the Solar System for some reason, high costs and accidents may, like nuclear energy, cause it to scale back and diminish to its current state of roughly 50 people per year to LEO.

Without the incentive of profit, which I doubt tourism could sustain by itself, I don't see how spacefaring ever gets off the ground. Maybe mushrooms found on Europa become an insanely expensive delicacy, or similar. But it seems astronomically unlikely. If the profit incentive can be found, then it could not be stopped, but it really needs to do more than pay for itself, and at a current pace of sinking $20B/yr into it without a return, ever, who knows if it will ever even break even?

Well, with the timeframes here, there exist only two options: "never" and "very soon".

So, yeah, if you want to argue for "never", it's valid. It's just talking about delays that isn't.

(But somehow the "no large enough group - and it means 100 or 200 people - will ever want this" argument doesn't look reasonable either. We are talking about an empty ecological niche and a timeframe large enough for biologic kingdoms to appear.)

You have fair points except for

> But somehow the "no large enough group - and it means 100 or 200 people - will ever want this" argument

idk who argued that, but it wasn't me. My argument is economic. I didn't make it but would make further argument(s) basically that 1) it's insanely dangerous, and 2) there's nothing out there, which together is really the same risk vs reward argument that is notably top heavy with a wide spread.

An economic argument is exactly the same as saying the people don't want it badly enough.

> An economic argument is exactly the same as saying the people don't want it badly enough.

This is false equivalence. Assume everyone wanted it to the maximum possible level of desire, and it is still possible that desire will be unfulfilled due to economics, namely, expense. You can't say of a home that someone can not afford means they did not want it badly enough. No matter how badly they want it, it is not possible for them to get it if it is beyond their means. Humanity may not be able to afford human-attended space exploration beyond LEO and, vanishingly rarely, the Moon simply due to expense no matter what the level of desire is.