Try running a business on that basis - where do the restores come from? 8)

We charge our customers for backup storage by volume and that includes an annual demonstration of recovery. We fire up some or all of their systems on our gear in isolation and show that they are reasonably functional.

Your teacher's comment is riffing on the well trod lines of: "heights don't kill people, it's depths that kill people", which is all about perspective. This is is not related to "guns don't kill people ..." which is about agency.