I don't think it has to be that far-out. Remember what life on New Caprica looked like after a year? Tent cities, open fires for warmth, pretty primative stuff. And I expect things would have continued to get worse before they got better, as tools broke and couldn't be repaired, the last of the scavengable material was scavenged, etc.

Which makes sense. Super-duper technology can be pretty useless w/o the basics, things like the ability to drill for and refine petroleum.

If the 13th really did land on and colonize Earth in isolation, I imagine it would have been a pretty big setback for them relative to the rest of the colonies.