re: Sometimes these guys come across as just plain greedy
We will go to space because it is the biggest stage upon which we can manifest our dreams...
Great line!
And we know for a fact that humanity will indeed try to manifest those dreams, and imho one planet will not be sufficient to support the effort. So I do think that ultimately the issue is survival.
If we stay in the crib, I'd wager things will get much, much uglier than they are now. Humanity is not pretty.