If Apple even attempted to do whatever nonsense you're suggesting, their market share would plummet to zero very quickly. Users just won't accept not being able to use their devices as they see fit. All serious developers would leave and then all that left would be just an iPad with keyboard. And no platform ever survived without developers.
This is obviously untrue, because what I described is already the case, and Apple is the most successful consumer electronics maker. They don't care about market share, they care about owning the most profitable customers in the market, which they do.
