Film Theory: The Evil Mastermind You Didn't Notice In Interstellar
3. Plan B (which Was The Real Plan All Along) Made Absolutely No Sense
We later find out that Dr. Brand always knew the gravity equation is unsolvable, which means Plan A - getting everyone off the planet in a ship, was a no-go from the start. That leaves Plan B - getting 5000 human embryos to the new planet and let everyone else on earth die.
Consider for a second just how ridiculous this plan is. The current human population in the timeline of the film is 6 billion, as Cooper points out. That's a lot of people currently being supported by a planet that NASA will have us believe is doomed to the point of impending human extinction.
The setting in the film looks far from a post-apocalyptic society where s**t is going down in a major way. Kids still go to school, there are still baseball games, and people in general are dealing with life minus a few privileges. Are we to seriously believe the idea that a population of at least 5000 breeding humans won't survive on earth to repopulate it? Not even in one of the numerous remote places and islands it is host to?
Even if we believe that agriculture is going to be affected on every single place on earth, our species were hunters and gatherers to begin with. Many such primitive societies still survive.
How exactly does life stand a better chance of surviving if we spend billions on sending 5000 babies under the exclusive care of NASA's machines to a new planet that will need to be terraformed first, rather than ensuring that a small population of humans survives on the planet where we are already... you know, for significantly less cost? It's either another blatant lie, or an eyewash.
But to what end?