For the last few years, pundits and analysts have argued that Apple may eventually combine its mobile operating system iOS and its desktop operating system OS X. Both late last year and early in 2015, several reports suggested that the merger would begin on the iPad Pro, a tablet that at that time had yet to be announced. The rumors said that the iPad Pro would feature the touch integration of iOS with the power of OS X to create a higher-end tablet. The device, the rumor mill said, would compete directly with Microsoft’s (MSFT) Windows-based Surface Pro.

While Apple did eventually announce the iPad Pro at a special press event last month, the company rebuffed hopes of an operating system merger. Instead, the iPad Pro runs on iOS 9 and takes advantage of some of its new features, including improved multitasking and split-screen view.

The decision to bundle iOS with the iPad Pro seemed to have been the final word on talk of an iOS-OS X merger. But alas, during an interview at BoxWorks, Box CEO Aaron Levie again brought up the issue with Cook.

“We don’t believe in having one operating system for PC and mobile,” Cook said, according to those in attendance. “We think it subtracts from both, and you don’t get the best experience from either. We’re very much focused on two.”

Apple did not respond to a request for comment.

The idea’s supporters have argued that Apple merging iOS and OS X may not be such an outlandish idea. After all, Apple has integrated some multitouch gestures into the touchpads that work with its MacBook line. The company’s mobile software has also taken cues from OS X. Both operating systems even sync their content between each other, ostensibly making a marriage between the two a bit easier to finagle.

Still, the idea of combining iOS and OS X flies in the face of sound product strategy, analysts argue. Trip Chowdhry, managing director of equity research at Global Equities Research, said that the idea of merging operating systems “does not make sense.” He added that combining the platforms means needing to hedge for different “form factors, [processors], and use-case scenarios.”

Chowdhry’s argument seems sound. The iPad and iPhone are touch-based, come with different processors, and provide different experiences than the company’s higher-end MacBooks, iMacs, and Mac Pro. Trying to bring the touch experience in iOS to Apple’s high-end Mac Pro desktop, for example, would be nearly impossible. Or, as Chowdhry puts it, combining Apple’s operating systems would be “total stupidity.”

Ian Fogg, an analyst at IHS, echoed that sentiment. He believes that combining the two operating systems would mean that Apple’s entire product lineup would ultimately suffer.

“Apple believes offering optimized user experiences for each kind of device is better than delivering a single, lowest-common-denominator experience,” he told Fortune.

Fogg added that Apple isn’t alone in believing that offering different software experiences on various device types is a smart idea. He pointed to Google’s (GOOGL) decision to bring Android to mobile devices and Chrome OS to its Chromebook computer line as further proof that the mobile and PC businesses live in separate environments.

“Beyond Apple, the other notable success is Google who also tailors their experience to the device type with Android, Chrome OS, and Chrome on Mac and Windows,” he said.

Mobile phones program director at IDC, William Stofega, took a more technical approach on why Cook’s decision is a smart one. He argues that the operating systems have been designed since their respective beginnings to power different kinds of devices. Combining the operating systems could create a whirlwind of trouble for Apple, which would force developers to “utilize new tools and reconstitute new apps”—a task they would find unappealing, to say the least.

Stofega also argues that in the future, the operating system’s importance could wane. The market appears to be headed towards a cloud-first model, where everything lives in the Internet and “data can flow anywhere and not be encumbered by hardware or OS,” Stofega aded. Apple, realizing that, sees little value, therefore, in taking on the arduous task of combining operating systems as offline software becomes less important.

“If the future is about anytime, anyplace applications on any device; why limit yourself by OS?” Stofega asked.

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