I didn't say they were running out of making money, but the days of just churning out a new version of Windows and Office every 2-3 years and counting on millions of reflexive upgrades are limited. And since more and more money spent on computing devices is _not_ being spent on devices where Microsoft has a dominant position (i.e., laptops and desktops and servers to a lesser extent), MS is rapidly losing market share even if their share of PCs is not substantially decreasing.

Microsoft's greatest competitor to Windows version X has been version x - 1 ever since XP came out (except for Windows 7 whose greatest competitor was version x - 2). With Windows 8, there is very, very little incentive to upgrade unless you want to use a touch-screen device. I would bet very few people even upgrade Window any more. 99% of the time they only get a new version of Windows when they get a new computer. I know that's been true for me for 10+ years, and I'm cool with that.

Consumer preference may be driving the move to app stores, but only because no other delivery mechanism provides that kind of end-user experience of being able to pick out an app, install it by pushing a button and knowing you're almost certainly not getting malware.

Oh, except for most Linux distros for the better part of 10 years.