Agreed. Federighi and his team are seasoned vets in building and delivering software to millions.

They aren't naive and know they need to balance end-user benefit with engineering's wishes for maintainability etc. Is the user going to see a vast difference in experience if they re-wrote the Settings.app? Swift is a language, not framework, so it doesn't offer the end-user anything worth caring about.

Swift will probably cost them more than it gains them in the immediate term, but the long-term is what Apple is all about, so I don't think they are concerned about this.