> it provides a beacon for humanity to dream

Not only that, for truly long term perspective its about mankind survival. Even that POS musk realizes that (at least he did, not sure where his psychosis got him now and don't care much TBH).

If we stay around just Earth, we will be eventually wiped out. Maybe not in next million years (or maybe yes), but but given enough time one of many ways that would happen will happen, from the sky or from processes happening purely down here, manmade or not.

Its not rocket science, its not some magical theoretical what-if, just hard facts when digging around a bit and looking at history. Anybody who has power to change things and decides not to should be treated accordingly.

Even if mankind is lucky with everything else, in 500-800 million years the sun's increased luminosity will render Earth uninhabitable for higher life forms (as we know them) [0].

[0]: https://en.wikipedia.org/wiki/Timeline_of_the_far_future