In the two-plus-hour Microsoft press event revealing the details of Windows 10, none of us on the ET staff can recall hearing the words Android or iPhone, or any mention of how Windows would be improving its interoperability with them. Instead, Microsoft hammered away at how it will be providing Windows-based solutions

The event felt like something of a throwback to the days of “Windows Everywhere” instead of Microsoft’s more recent positioning as a devices and services business. I’m sure Microsoft thinks it can follow a Windows-first mantra and still successfully incorporate Android and iOS users into its ecosystem, but that involves a lot of wishful thinking.

Joe Belfiore — as always — masterfully demonstrated Microsoft’s new applications for Windows 10, emphasizing their excellent cross-hardware-platform consistency. The unified vision of desktop, tablet, and phone platforms was a soothing change from the often disjointed Microsoft presentations of years past. It was as if Microsoft is determined to out-Apple Apple, by providing a seamless, Windows-branded, experience across every piece of technology you touch. If the demos — and the energy Microsoft is putting into incorporating feedback through its Insiders program — are any indication, it may well pull it off.

However, even if Windows 10 delivers at a technical level, the massive effort of merging Windows Phone and rewriting all of Microsoft’s Windows applications using the Modern interfaces will be for naught if Windows doesn’t catch on quickly and massively in the mobile market. With less than 4% share of the smartphone market, and not much different in tablets, that leaves well over 90% of Microsoft’s customers who are currently more interested in better interoperability with Android and iOS than in another iteration of mobile Windows.

If Microsoft had the luxury of time, it could afford another bite at the mobile apple (pardon the pun), and rely on its desktop dominance to pull it through, but Google and Apple aren’t going to give it the time it needs to keep trying and missing. As the cloud becomes the center of our lives, and mobile devices our favorite way to interact with it, Microsoft’s desktop franchise is a depreciating asset. Microsoft thinks it can both live and breathe a Windows-first, Windows-everywhere focus while still providing competitive services to those with phones and tablets on other platforms.

History says that it is nearly impossible to do both well. Companies typically have to choose between architecting for open, interoperable, systems (as Google has done historically), or providing a high-quality, end-to-end experience (like Apple does). As exciting as Windows 10 is, and as successful as it is likely to be in replacing Windows 8 on the desktop, it is a stretch to see how it will break through in the mobile market. If it doesn’t, Microsoft will have squandered more time it could have been spending building the world’s best OS-independent ecosystem for consumers and businesses instead of rolling the dice on mobile Windows again.