I don't believe its silly at all.
We are talking worst case scenario. I have my steam games backed up on a external connected to a laptop in the other room. This machine dies just reinstall from that.
Bought Torchlight for $5.00 during the Steam special and got the steam files from my cousin. 1 2 3 Installed. Copied it onto my N97 when I visited him two night ago.
I love the fact that with a steam licence you will actually FOREVER own the game.
I bought the Baldur's Gate saga a few years back and well... those discs are stuffed. now I cant play it anymore for old times sake even if I wanted to. - Steam also does a great job making sure older games run well on newer machines. (citation needed :P - thats just what ive found)