"The time for that move was 2013. Alas, it didn't happen, so it's on our list."
The past decade, MS has made a habit of waiting 3 years to respond to any market activities of its competitors (e.g. compare the release dates of Google Docs and Office Online). They demonstrated Surface computing YEARS before anyone else and then SAT ON IT, not doing anything with it until 2+ years after Apple, then Android, ran with tablet computing (a very close relative of Surface computing). To be honest, i'm not sure what's keeping MS afloat. They are becoming less and less relevant in the world, quite possibly for the reason the author mentions: that they assume everyone wants a single-platform solution to all their problems. If that's what they continue to believe, and act on, well... so long, Microsoft!