The Microsoft of old would have died out eventually. What we are seeing is not something you see often - a behemoth of a company doing a 'pivot'.
What would you do remain relevant in the face of the majority of the internet services not going anywhere near Microsoft for material income?
After a few generations raised on smartphones and tablets without any Microsoft apps, Microsoft Office would just be a curiosity their parents used, like Corel Draw or dBase.
Fortunately Microsoft has taken note; there's rumor of Android Office apps, and the latest version of the Surface tablet is quite popular.
Microsoft, and in particular, Office is still going strong, but the stranglehold it had in the 90's is gone.
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Google may want businesses to pay, but going to docs.google.com and using your personal email address works just fine - much to the chagrin of IT departments everywhere.
Google Docs doesn't hold a candle against it while LibreOffice can barely sneeze in front of it.
What non-technical users request won't matter, they will ask for whatever they are familiar with and complain if any icon is moved just slightly.
I like Google Docs as much as the next guy or girl, but I find this hard to believe when we had to end a meeting several minutes into it when the Google Doc displayed an http-500-style error when trying to load a spreadsheet.
MS is still corporate-centric in the US, and popular in foreign countries where Apple stores don't exist in large numbers.
In the US, perhaps. Where I study, I can count the number of people owning MacBooks on my fingers. They're still way too overpriced/lacking in hardware compared to PCs at the same market rates.
All of that said, outlook integration to office365 is actually worse as a mail client than it had been in the past with self-hosted Exchange. Counts don't update properly when you "delete all" from a folder, and even then it's inconsistent. I know it's to allow for better scale/resource control on the servers but it's still very annoying to say the least.