I don't know how true that statement about sitting idle is "the worse thing that can happen to an airplane."
I can think of a lot of ways to make it worse.
I bought a 75hp continental engine that had only 60 hours on it since being put on a plane in 1976. And in the last 10 years it had only 10 hours put on it. Yet it started immediately, and the compression was above 70/80 on all cylinders.