I don't think there is a real slowdown in demand for PCs.
The real reason no one is buying is they all come pre-installed with the Windows 8 crap.
Go into pc world / john lewis etc and you have row after row of unbuyable rubbish. And yes, even with 8.1 update-whatever, it's still rubbish.
All the pros I know have switched to macbooks and run Win 7 via vmware or parallels. And after using a macbook's touch pad, there's no need for any touch screen crap.