Re: What PC death spiral?
How many people bought a PC just to get on the internet and do some e-mail? Those people are usually perfectly well served by a tablet or even a phone. Better even because those devices are far cheaper and don't require the level of maintenance that a PC has and that's the attraction. Those of us who make our living programming for instance will still need a desktop but what about those people who just work in Office docs? This is why MS is pushing so hard in the cloud space with 365 and put Office on platforms other than Windows/Mac including iOS and Android. They need people to keep creating and editing documents in Office formats otherwise they really will become irrelevant. The fact that they're making phones which can be a desktop too just reinforces this but my personal opinion is I don't like the one device/OS fits all approach and have a phone, tablet, laptop and desktop and they're all for different needs despite there being significant crossover.
The money in the market is being divided beyond microsoft's grasp where they used to be the only game in town and the PC the only tool. Neither of those are the case now and that's why the PC is a shrinking market with lower turnover rates. There's still plenty of money to be made but MS doesn't control the software world any more. Windows isn't the only platform choice and that's better for everyone.