I think the semi-obvious reason mobile OS's are "applicaiton-centric" and not "document-centric" is the monetization of mobile applications. Apps are the big ca

I think the semi-obvious reason mobile OS's are "applicaiton-centric" and not "document-centric" is the monetization of mobile applications. Apps are the big cash cow on these operating systems, whereas "documents" or people or files can't really be monetized in the same way. The downside of the app-centric thing is an odd sort of discretization of the user-experience via apps. PC's now feel much more free-form in that user interaction is still largely driven by files (i.e. "documents").