The economy is doing fine now and the PC market has only began to start shrinking. No one in the tech industry, even Intel and Microsoft, are seeing growth potential in the PC industry, but perhaps you have some special insight that we are all lacking.
The economy is not fine. You can't fix a credit fueled housing market bubble and subsequent crash with $4T in more debt. The Fed papered over the worst of the crash to minimize the political consequences. I don't agree with all of his analysis but http://danielamerman.com this site has some good explanations of what is going on. See his discussion on Hiding a Depression.
The PC market can't grow forever, how close it is to saturation I don't know but there is still a lot of money to be made in mature markets like autos, etc. MS needs to get its act together and defend its market share or it might end up like GM.
No need to be americacentric, the PC market is stagnant even in China, which didn't go through any of these crashes (yet).
I'm not speaking for MS, but I think they want to be seen as a growth company, not a stable, mature company. They want to maintain their market share, but the "opportunities" for new growth probably lay elsewhere, so you'll see investment away from PCs into areas where new money can be made (while still trying to preserve old money, of course). Even the car needs a new remake to create new market share and hence opportunity; e.g. Tesla and electric cars.
