In an interview published in The Sydney Morning Herald today, Apple CEO Tim Cook suggested that Apple is not working toward eventually running the same operating system on Macs and mobile devices like the iPhone and iPad, counter to widespread speculation.
The interview took place at the education-themed event in Chicago at which Apple unveiled the last iPad. Here's the relevant quote from Cook:
We don't believe in sort of watering down one for the other. Both [the Mac and iPad] are incredible. One of the reasons that both of them are incredible is because we pushed them to do what they do well. And if you begin to merge the two… you begin to make trade-offs and compromises.
So maybe the company would be more efficient at the end of the day. But that's not what it's about. You know it's about giving people things that they can then use to help them change the world or express their passion or express their creativity. So this merger thing that some folks are fixated on, I don't think that's what users want.
Earlier this year, Bloomberg ran a report saying that Apple will soon unveil tools for developers that will allow deploying an app for both macOS and iOS machines. Apps that target both platforms would be usable with either a touchscreen or a mouse/trackpad, depending on which device launches them. While some outlets are saying Cook's statement debunks that rumor, that's not necessarily the case; apps that support macOS/iOS interoperability don't require a unified operating system.
However, the quote might clarify Apple's plans to develop its own processors for at least some Macs to replace chips made by Intel—another rumor based on a Bloomberg report. Commentators (myself included) were quick to speculate that, should Apple make its own Mac CPUs, it would base them on ARM in part to bring macOS and iOS closer together. Cook is suggesting here that Apple has no plans to bring macOS and iOS that close together.
That doesn't mean Apple won't go with ARM, though. It already has years of experience engineering ARM chips for iOS devices, and there are serious roadblocks to moving forward with an x86-64 architecture instead, barring an unlikely acquisition of AMD.
Apple competitor Microsoft began the process of merging its tablet and desktop software long ago—a process that is mostly complete. While Microsoft has produced different versions of its Windows operating system to run on different architectures (such as x86-64 or ARM), Windows now offers both a tablet and a desktop mode, and many popular Windows-based laptops ship with touchscreens and convert between the two modes on the fly with pivoting or folding designs.
Apple has not launched any touchscreen Macs, and while macOS and iOS now share some services and other features (like the APFS file system), they are still very different operating systems for very different use cases.
In the Sydney Morning Herald interview, Cook said he uses both a Mac and an iPad, and he uses them in different contexts:
I generally use a Mac at work, and I use an iPad at home… And I always use the iPad when I'm traveling. But I use everything, and I love everything.
Apple still sees tablets and laptops as different devices for different situations, and Cook believes that trying to serve both devices with the same operating system would result in too many compromises, at least for now. The company has changed course before when the market demanded it, though.