The trouble is, they're both right. We're a species with the technology to live in space, but with only the resources for a precious few to do so. No matter how bad things get, we can keep millions alive in a rich country by seawater alone (hydrogen, algea, electricity).. But...
The majority of the rest of humanity and all living things on earth will die. So it isn't a matter of who is right but how many we can save in the process.

Also, "colonizers incarnated human greed as corporations..." - poppycock. Our journey to the limits of growth was a foretold conclusion when we harnessed fire. To even include that quote is to show which part of the internet captured your eyeballs.