That's going to keep two kinds of people from ever moving to it as their primary computing device: people who care about freedom, and power users who care about versatility and complex work flows. The latter includes most developers. You just can't do that stuff on iOS. You can barely even run your own apps on it.
I suppose you could push a model where all the interesting stuff lives in the cloud or headless metal servers and the iOS device is a portable terminal with apps and the Web as sophisticated terminal emulations more or less. Think of an app or a big JS site as a giant analog of a VT macro.
I see PC sales declining and then leveling off after having lost most casual and low end users to tablets and mobile.