[tseliot]

My different interpretation of that metaphor is that the wasteland is by definition an infinite sink. No amount of resources can make all of it anything other than wasteland. On the other hand, finite resources can make part of the wasteland into a vault, which may be larger or smaller, more or less attractive to different people, more or less interoperable with other vaults etc. But a vault nonetheless.

[FelixP]

There's probably a lot of opportunity in simply connecting said vaults and making switching costs lower, with fewer mutants, radscorpions, and less radiation to endure between vaults.