Then, without wishing to be rude, you haven't been paying attention. The vast majority of customers don't care about upgrading their PC's and haven't done for some time. The PC has become a device and that's the way it should be for the vast majority of users. If an iMac breaks you take it to the Apple store and either get it fixes under warranty, pay for a repair or buy a new one. It's time for people like us to realise that the... oh, call it 15 year spell from around 1995 to 2010 where the PC became essential but still relied on technical knowledge to work and maintain it was a blip. Computers should, dare I say, just work and require no more specialist knowledge to own than a car. Very very basic maintenance tasks are done by the owner but for anything more that dedicated service centres are used. How things work isn't really important, what it lets you do is.
Sure there will always be a small number of users who want to open their PC's up and either change or repair them on their own terms. But that's a tiny percentage of the total user base, heck even a lot of 'pro' (i.e. business) users don't do that any more with 3 or 5 year warranties being taken up instead. When it breaks outside of that it's on a replacement schedule with funds set aside in the budget for that very purpose.
On a related note I've never been able to figure out the dismissive attitude to attractive looking desktops. Sure, when I'm sitting in front of my iMac (2011 model with a new 27" on order) I can't see the sides, fair enough. But every time I stand up, every time I walk past the home office or do anything in that room that doesn't involve sitting in front of the screen the design is clearly visible. Am I buying an iMac to show off to my friends? Nope, not at all. But I am buying it (at least in part) because I like having things in my home that are well designed and in a very small way are enjoyable to look at. I've had self-built tower PC's since, yikes, 1998 and while they may give the most bang for the buck my priorities have shifted. Nowadays I'd much rather pay a little more for a great looking near-silent computer that doesn't clutter up the room. Of course I understand that others have different priorities and that's fine but I do wish that sentiment was shared a bit more than it is.
