Yes, and Grumman’s point is that maximizing humanity’s chances for survival may entail developing the necessary technologies instead of going off half-cocked shooting people into space.
“Maximizing” anything means you have an objective way of measuring progress. Your idea seems to be “let’s just toss people into space until we get it right”. How is that supposed to be an optimal solution?
Remember that we have potentially thousands, millions, or even billions of years before a species-ending disaster threatens the planet. A big comet? Even then, there’s a fair chance humanity, as a species, survives. May lose some technology and certainly millions if not billions in lives, but we stand a good chance at survival (and conditions would still be better on Earth than anywhere else for human habitation).
And even if it comes in 500,000 years, that’s still 50 TIMES the amount of time we’ve had any sort of civilization. Why does that imply we need to push 50-100 year plans into 10 years?
Until we have the means to evacuate people from one such pocket to another, any reduction in the chance of total extinction would be offset by an increase in the chance that part of humanity would be completely wiped out - an asteroid hitting Earth might only wipe out half of humanity, but it also means an asteroid hitting Mars will wipe out half of humanity. And the technology base that would enable such evacuations is exactly the sort of thing that would make establishing these colonies in the first place a hell of a lot easier.
I think in order to get enough people behind it to make it possible to fund it, you have to show them what Humanity gets out of it. Long-haul stuff doesn’t work very well, because politicians and voters quickly lose interest (or get yelled down by those who do) when the scope of benefit exceeds their lifetime/generation.
We know we can put footprints and flags on another body because we did it with the Moon. So, yawn.
Even if we can get to Mars and sustain life there for a handful of people, what’s it mean? Are we practicing for when we can explore other worlds? How likely is that to happen, when we haven’t made it to the nearest star, to say nothing of worlds we could inhabit? So, if we’re not likely to need our Mars skills on another world for an eon or more, what are we DOING on Mars? It’s fairly resource-poor, so I don’t see pitching a colonization effort with any success unless and until the situation on Earth is far more dire than a majority of people believe it is.
As much as I love the idea, I don’t think we should go for it until we make some socioeconomic and technological quantum leaps.