I sort of agree. If we imagined a world thousands of times more wealthy than the present one, I think you'd probably see a Martian colony kick off more or less

I sort of agree. If we imagined a world thousands of times more wealthy than the present one, I think you'd probably see a Martian colony kick off more or less "just because it's there." But absent any return on investment, the available resources today are orders of magnitude too small to make a go of it. In any foreseeable world, any kind of substantial off-Earth human presence (more than say 200 people) is going to require a substantial practical value to justify it. Pure science or "just because it's there" or fulfilling the childhood sci-fi dreams of various people are not going to cut it. Which bums me out too! I have childhood sci-fi dreams. If there's a path to large-scale (or even medium-scale) human presence off Earth, it's something like solar power generation or asteroid mining.