I still don't understand how a bunch of stored-to-file object graphs "dirty the code base" but I guess you are right -- it is a preference thing. Believe me, I have weirder quirks than that when it comes to coding.
Your example, however, is probably amongst the worst to support the argument you are making. Here are the steps to create a tab bar view with four tabs, each containing a navigation view, and those containing alternating table views and plain views:
- drag out a UITabBarController
- remove the two default UIViewControllers instantiated with it
- drag out to the tab bar four UINavigationControllers
- select each tab and drag out to the center area of the view a UITableViewController or UIViewController
- customize to your heart's content
- there is no step six…
In my guestimate this will take at least 20 lines of boilerplate code, even with the minimal amount of customization. And you’d be missing out on all the rest of the benefits of NIBs, like the ability to see (and to some degree test) your UI without having to build and run your application or the ability to send it off for localization to a collaborator.