"The "arguments" were to work, to live, and to survive. The first two were vague nonsense. The "to survive" argument has been argued much better by people on this website, and I still think no one has articulated why we need viable populations off-Earth in the next 50-100 years in order to meaningfully reduce the chance of human extinction. Gary's "we might lose the technological capability/will to leave Earth" (my paraphrase) is the closest, but I'm not persuaded. "

I don't think we are in danger of losing the technological capability.
And I think we *could* stay on this planet for the next 100 with no significant threat to human existance.
But the way I see it, we probably won't stay on this planet for the next 100 years.
It's like arguing in the early 1900s whether horses are going to remain the main mode of transportation until the end of time.

I think a more important angle to this is as a govt should we continue to attempt [whether intentionally or unintentionally] to hinder space development.
For instance, do we as citizens of this nation have the right to go into space?
What would think if you are permitted to own a car, but you could only drive it once a week- oh but you can drive around on your property as much as you like. Or say every time you want to drive more than fifty miles, you had to send in papers, and get govermental approve for your drive plan through the public area [and they promise to do much better job at quickly approving it than compared to rocket launchs- they get you your approval back within a month].
Car are dangerous, you know. They killed about 40,000 americans last year. If we restricted the use of cars, less people would die [from car accidents].

The only time a space launcher has killed a significant number of people was when a Russian head engineer, decided to put themself dangerously close to the first launch of a rocket, in order to prove he had confidence that the rocket would launch safely- and of course the sucker blew up and kill him and all the rest of the people who didn't want to appear less confident.

If NASA shut down tomorrow, it wouldn't be the end of the world. The really important issue is when will American citizens be permited by the govt to go into space.