That’s all true, but I still think it is a reasonable goal. Having the technology to be self sustaining in another world has the ‘side-effect’ of letting us be

That’s all true, but I still think it is a reasonable goal. Having the technology to be self sustaining in another world has the ‘side-effect’ of letting us be self-sustaining on earth… reducing the risks human pose to ourselves. That said, ‘colonizing’ the artic or shallow ocean floor probably accomplishes most of the benefit for a subset of the cost and risk. The only real benefit I see to space over the attic is that off worlding mining and production could be a benefit in itself.