They now use most of the same device busses so I'm curious how Macs are not expandable?
I mean: IDE, USB, Firewire, 802.11b, 56k modem, CD/DVD-ROM, both digital video and whatever the older (rgb?) thing is. What doesn't expand? Heck, the desktops flip open with a latch making component installation take a second - no screwdrivers required. I don't get your point.
Plus, I kinda think MacOS X is worth the price differential. Because while you may get yourself a PC for X dollars, it comes with a built-in money tap (halting regularly to demand upgrade money) that flows to MS. In the end you pay more unless you run non-ms software (which you still generally end up paying for once except for a few rare exceptions).
Then there's the value thing. Software I need to run doesn't run on linux. So the relative value of the PC is zero. Not a good value prop.
I don't think your assertion holds.
And what does this have to do with innovations that change the definition of what a computer is?