This is just an opinion, so please don't badger me for evidence. I'm not trying to troll anyone, so do reply if you disagree with me.
It seems to me that Microsoft has no idea why people have been buying their products this whole time. In the last few years, they've been banging on about the "experience" of using Win7/8/Phone, as if the people who buy Microsoft products do so for the unique Microsoft Experience. In other words, that they buy Microsoft products for much the same reason as one might buy an Apple product. I would argue that this hasn't been the case since the excitement of Windows 95. Even XP was only a small step up from 2000 at the time. By and large, people buy their products because a) they believe it to be pretty solid and/or b) it's the standard. If more solid alternatives exist, and the MS product isn't the ad-hoc standard, they don't make a big impact in the market.
Now, you might say that no, they've been talking about the "experience" because that's what all the cool, profitable kids are up to. That may well be the case, but if you watch their adverts, it goes a step further than trying to convince you of a top-quality experience: they tend to allude to "the Windows/Office/MS Bob experience you love", as if it were an existing truth. It's always struck me as curiously arrogant, coming from a company which deliberately strangled the competition to gain its dominant position. What I don't know, however, is whether they've misread the market that badly, or they're trying to get people to believe there already is such a demand for a specifically Microsoft experience, in order to create this demand.