@Threats to the PC
"obsolete and ersatz software like UNIX"
Don't make me laugh. If you want real work done (reliably) use a UNIX or Linux box.
I have several really old, relatively slow (by today's standards) HP-UX servers doing easily 10 times the work of brand new Wintel machines, and they do it without constant preening and without being rebooted three times a week.
And the reason OS-X is so stable? That'll be UNIX too!
There's nothing wrong with basing an OS around UNIX. Often it's the graphical environment that needs some design work - a more user focused approach. I often wish M$ would swallow their pride and follow Apple and Google's lead - a Microsoft graphical environment on top of a secure and robust Linux platform would be a winner IMO.
Far from being 'obsolete', UNIX (and OS based on the UNIX model) is resurgent. Windows hasn't lived up to it's promises and people just want reliable systems that work ... and don't need 2GB of RAM and a dual core processor just to run a browser!
</rant>