The big companies are hooked on the idea of renting things to you. I bet the old fashioned way of: have product... a sale... upgrade the product... another sale... product breaks... customer buys a replacement... That must result in more money than renting.
I don't think so. If you're renting they effectively force you to upgrade even if you don't really need to. Well they say "free upgrade!" but guess who's paying for it anyway.
I think the industry would like to move everyone over to tablets etc, they imagine the public never aspire to do anything creative and will buy any sparkly gadget you throw at them, I don't think they're finding it quite that easy though. There's been a resurgence in tinkering lately in the form of the "makers movement". Maybe it's testament to the fact that hobbying all but died out 20 years ago, that the next generation had to invent another name for it.
When we had computers in the '80s we used them for programming and all sorts of stuff, because development was simple and cheap and anyone could do it if they were willing to read a book. Then it became big business and nobody imagined doing it anymore except if you got a degree in it and god a job in the industry. Now in the era of smart device proliferation, anyone can program again. Every web browser has Javascript. You can get Android dev kits for free. There are abstracted high-level languages for everything. And kids are realising, once again, that "hey you can actually do all sorts of cool stuff with computers!" Because you really can, even with a lowly 800MHz Arm, which has more power than was imaginable when we were kids. Hence the Raspberry Pi.
But the fact is, I think, that nobody needs the very expensive top-of-the-range desktop PCs anymore, not just for facebook &c, but for doing cool stuff too. I use a desktop PC myself out of personal preference (it's what I'm used to), it's quite old and it was "entry level" when I got it (I always hated that euphemism for low-spec, I'm hardly a computer novice I'm just aware of how little power I need) but more and more people grew up with laptops, and are used to them. I don't think PCs are anywhere near dead yet, but the days of needing an ominous full tower system under your desk that sounds like a vacuum cleaner are over. Thank goodness.