>...Apple... [having a fragmented operating system strategy].... At some point, this may have a negative impact on the Apple ecosystem. Interestingly, Microsoft has made attempts to solve this same problem with Windows 10 across the corresponding Windows device ecosystem.

I don't think that's a fair analysis of their strategies. At this point I think it's pretty clear that Microsoft's strategy to port desktop OSes on to hand-held devices was absolutely the wrong way to go, and Apple's strategy of building an entirely new custom interface for mobile was a crucial advantage. Shoehorning two fundamentally different UI paradigms into one platform might have some theoretical advantages, but in practice it's failed.

As for sharing files, that's pretty much solved for iOS now. For example in the Adobe apps, you just hit 'Share' and can send your work directly to one of their desktop apps via Creative Cloud. Then there's Dropbox, iCloud is getting usable and there are many other sharing services.

As for the apps not existing 'and may never exist', iOS has one of the richest developer and software publisher ecosystems on the planet. IBM is going all-in on developing enterprise iOS apps and even Microsoft has jumped in with both feet. The iOS version of Office is the real thing, not a cut-down emulator, and has Sharepoint integration.