ending doesn't make sense

[Battlesheep]

I'm wondering why they didn't try to bring anyone else back. They had access to MANI, and there were apparently a number of people there who had X-keys implanted, including researchers. Seems like they could have scrounged up some intact X-keys and increased their number, maybe even finding someone with the knowledge to maintain and improve the Extend machine. They could have even solved the aging problem by just copying their data to a blank X-key of the older model, i'm sure MANI had some of those lying around.[\spoiler]