I'll simply refer you back to the internet where you have videos, gameFAQs, forums for technical assistance, etc...
There is no logical way you can argue your side of this argument beyond wanting a digital copy of it for true backup purposes in case your disc goes bad. Many media such as DVDs no longer have this fair use clause and it is illegal for you to back it up.
Not only that, but you can also rent the game from a variety of places. Treat that as a demo if you like. That's all I'm saying.