[saurik]

That isn't what it ever seemed, on early iOS at least? They would have every single app on the device using a private API -- like UIScroller, or UIWebDocumentView -- and then they would let all of their end developers screw around with the new UIScrollView, or UIWebView, and it would take a few years for their screams to result in the good design aspects from the private APIs to be begrudgingly given to the masses. At some point, a couple apps -- often starting with the Calculator app, which always seemed to be written by an intern -- would get ported to use the APIs the end developers had been trying to use for years, and if that worked out, Apple would start actually porting their apps off the internal APIs to the "finally good enough" public ones. It was honestly ridiculous... you'd see people talking about some extremely limited API, such as UINavigationController, as if it was somehow amazing... but you'd then have to point out "so why isn't Apple using it anywhere?" and the zealots somehow wouldn't even understand that that was possible :/.