@Chameloshi: The vault experiments were to help the Enclave learn how people would react to scenarios involving prolonged isolation as they survived in orbit. The Enclave only existed to protect themselves from nuclear war; they had no motive to start it.

@Fenrick: Where do you go to survive if the whole planet is uninhabitable? More specifically, what would you think about if you were someone living during the Space Race who wanted to live after Earth was scorched?