It's been a decade and more since that was even remotely true (if it ever was). Back in 2008 the average survival time of an unpatched internet facing XP box was around 4 minutes [0]. Pwning an unpatched XP box was (very marginally) harder than pwning a system with no security at all. The Morris worm (Edit: which is heavily mentioned in TFA, my bad) [1] got loose in 1998. There's some interesting stuff regarding whether such risks are comparable with things we use insurance to hedge at [2].
[0] https://isc.sans.edu/diary/Survival+Time+on+the+Internet/472...