title: ViewController's view is nil; using subviews only; is this ok?
body: <p>doing this in AppDelegate:</p>
  
  <p><code>viewController = [[RootViewController alloc] initWithNibName:nil bundle:nil];
  </code></p>
  
  <p>Is there any problem with <em>not</em> defining a viewController's view (using <code>setView</code> or <code>viewController.view=</code>) and simply adding <code>subviews</code> of the view only? What difference does it make if you put most of your app displayed content in a subview rather than the main root <code>view</code> property itself?</p>
  
  <p>is it a problem if <code>viewController.view</code> remains <code>nil</code> (or whatever state it is in if there is no implementation of <code>loadView</code> or a nib) but you actively manipulate subviews of <code>viewController.view</code> ?</p>