It would be very nice if hospitals et. al., airplanes, ships and critical infrastructure could be run like that... people (primary politicians) are however stupid so they are not.
Some of the kit (xp), I maintain is run like that, disconnected from the internet, hardware firewalled and only a specific port open for a very specific purpose, everything locked down, hence why non of it succumbed to the NHS malware, while brand new win7 based systems were dropping like flys.
But like you say, most systems are just plugged into a port in the wall on a wing and a pray and as long as you suffer the OS updates and keep you antivirus updated, all will be fine.... or maybe not.
Biting the hand that feeds IT
