Both. (I'll play devil's advocate, if that's ok.) What matters most? "Computing operating systems" or "desktop market share"? I believe both are vital to the

Both. (I'll play devil's advocate, if that's ok.) What matters most? "Computing operating systems" or "desktop market share"? I believe both are vital to the long-term success of any competitor, Microsoft, Google, Apple, or "other." If Google or Apple did not deliver a good UX on Windows Desktops, the resulting lost opportunities would severely curb their success in "computing operating systems." Meanwhile, Microsoft owns the platform they deliver on. Can Microsoft use that to their advantage? Logically they can, but the ethics of their actions may result in US DOJ antitrust action. If Microsoft does not deliver a good UX in mobile, tablet, and ultrabook markets, their future relevance on the desktop is threatened. This is where I think you and I disconnect: I believe Microsoft is now waging a two-front war and is being squeezed by the resulting pincer attack. Microsoft has to simultaneously innovate in new, fast-moving markets like mobile and tablet, while acting like a benevolent 800-lb gorilla in the desktop OS market. It's not impossible to do, but it requires a combination of finesse and balls that Microsoft seems to be lacking, based solely on the stock price history for the 2002-2012 timespan.