I might be a counterexample to your perceived overlap. 3 points:
* It seems that, as a species, we have deep issues rooted in our tribal upbringing. Reaching a global actionable consensus seems as hard (if not harder) as colonizing another planet. The internet only catalyzes the "us vs they" thinking people struggle to get rid of. In one of its many incarnations, it's a nurture of horribly mistaken worldviews — and here I imply climate change denialism, in context. But also flat earth, etc.
* Viewed independently from antropogenic climate change catastrophy -- living on another planet would be extraordinary achievement, would you disagree? Launching a "toy" helicopter is kinda cool, but... living? For some of our greatest ancestors, the coolest achievement has been building millenia-lasting megastructures. Our generations are building fusion testbeds, orbital telescopes & commsat constellations; why wouldn't, say, a giant Earth-shaped globe monument on Mars be great? Perhaps not a globe, yea... but a Statue Of Liberty? Dao temple maybe? A hammer-and-sickle impact crater giga-egraving? Whatever.
* Both viewed together, rationally, Mars colonization is an option to escape extinction on Earth. Not a priority, sure; more like, a backup-of-backup-of-backup plan -- for when all else failed (see point 1). It's not like we can do it soon, either; advance preparations and long practice needed. I won't express any judgement of viability. I do see, however, how ambition and inter-tribe competition can drive this plan to a ready state (see point 2) -- sooner than fossil fuel combustion stops across the world.