When I purchase a music CD, software program, or DVD movie, I always make a fair use backup copy, and store the original for archival purposes. Why is that? Well, for one thing, disks become damaged, or wear out from use. However, what I have purchased, and paid good money for is not just a silver piece of plastic with some writing on it.
When I purchase a media product, what I am really purchasing is a LICENSE to use that product on one device at a time. Under that legal theory, as long as I possess the original, and thereby the license, I can legally make one copy for personal use, as long as only one is in use at the same time. So I do not find anything legally or morally objectionable about making and using a fair use copy, in order to protect my investment.
Now, it is true that under the Digital Millenium Copyright Act, the mere act of circumventing encryption or other DRM is now a criminal offense--even if the underlying purpose falls under a legal exemption (such as Fair Use rights). However, let's face it. Have you ever heard of someone being prosecuted under the DMCA who is NOT actually violating copyright law, and selling/distributing/uploading copyrighted content? Guess what, neither have I.