I think the dreams of being multi-planetary are similar to buying doomsday bunkers in New Zealand. I see it as a desire to escape the problems of earth.
I would ask a question to Anjum Choudhary, "If there is a colony on Mars, and your ideology got hold of major countries on Earth, would you try to convert those on Mars?". I think the answer, undoubtedly would be yes.
Humanity has much to resolve on earth, if we go multi-planetary before we reconcile then all we would end up doing is make our problems multi-planetary.
Unless few people escape earth and destroy earth so that there won't be anyone following them. Equivalent to you first going into a safe bunker and then nuking the world, wait out the nuclear fallout to emerge. But then you would be pure evil.
I don't know if they have thought this through. On the scale of centuries, not quarter ends, all they are doing is working for those with higher rate of reproduction.