Luckily humanity has enough resources to pursue multiple goals simultaneously

Not this one. To create an outpost off-planet capable of sustaining human civilization at its current level in the event something happened to Earth would consume our entire economic output for many years, if it were even achievable.

Or it would consume a tiny fraction of our economic output for several generations while maybe also throwing off some sweet tech that is useful back here on Earth.

Do we have that long?

Who knows? Better get started sooner than later.

All your stuff is here, sure. What about your great-grandchildren?

I admire your optimism.

Could just as well be pessimism.