I'm new to science-fiction and I'm intrigued by the consequences of "Plan B" in the popular movie Interstellar. "Plan B" means transporting a supposedly sustainable population to a habitable planet outside of our solar system because the Earth can no longer sustain life and no other options are viable.
This and this address the question of how the "Plan B" colonization would take place and how colonization can work at all. My question is about why we would colonize if it meant a substantial technological setback.
The background to my question is this: Regardless the nature of Edmund's Planet, but assuming it is habitable, what would life have been like? I'm specifically curious about the relationship between humans and the technology that got them to the planet. Would they be able to make (sustained) use of it and reproduce it locally given they have access to the materials needed within their surroundings? The transfer of knowledge seems achievable using computers brought from earth, but would they have the capacity?
Imagine, therefore, being stuck on a planet lacking the chemical composition necessary for modern technology to persist while colonists possess the full (now useless) scientific knowledge to produce that technology. It would be ironic because Interstellar's main protagonist is just that: a very well educated man forced to be a farmer. And he's not happy.
My question is therefore: Assuming the colonized planet's resources would not support continued use of modern technology, why would we establish a human colony on another planet without the continued benefit of modern technology? Why would we opt for people to be (e.g.) subsistence farmers without the means to evolve the technology (and thus the society) they once depended on?
The reason I ask is because this situation is intriguing from a narrative point of view.