>Or something has been compromised or exploited and you've had no idea because it's not something obvious like opening your CD-ROM drive automatically.
This is addressed two paragraphs after the one you've quoted.
This is addressed two paragraphs after the one you've quoted.
And it's equally an incomplete assessment based on the same "This is fine" attitude. The computer could be participating in a botnet dedicated to bring down the network in hospitals or steal their sensitive medical data, and the author would never know.
Also you're missing the obvious solution, using a long-term support system with a robust audit process and well timed security releases. Author's setup will NOT be safer than that.