We don’t waste time thinking, ‘But it should be one [interface!]’ ‘How do you make these [operating systems] merge together?’ What a waste of energy that would be,” Schiller said. But he added that the company definitely tries to smooth out bumps in the road that make it difficult for its customers to switch between a Mac and an iOS device. For example, making sure its messaging and calendaring apps have the same name on both OS X and iOS.
To say [OS X and iOS] should be the same, independent of their purpose? Let’s just converge, for the sake of convergence? [It’s] absolutely a non-goal,” Federighi said. “You don’t want to say the Mac became less good at being a Mac because someone tried to turn it into iOS. At the same time, you don’t want to feel like iOS was designed by [one] company and Mac was designed by [a different] company, and they’re different for reasons of lack of common vision. We have a common sense of aesthetics, a common set of principles that drive us, and we’re building the best products we can for their unique purposes. So you’ll see them be the same where that makes sense, and you’ll see them be different in those things that are critical to their essence.”
Apple executives - January 22th, 2014.
Happy to see that Apple isn’t considering merging iOS and OS X. Look at Microsoft and Windows 8 (for PC and Tablets) for a spectacular failure in this regard.