I agree, you should be allowed to make a backup copy.
Here in the UK, it's called fair dealing.
Our rights as consumers aren't protected at all. DRM almost directly violates the consumer's right to make a back up copy.
Then there's the problem that you may no longer be able to use the material you've purchased when the vendor stops supporting it. For example Windows XP activation requires contact with Microsoft but what happens when they finally stop supporting it? If I need to re-install it on my PC, I'll no longer be able to activate my copy. My only legal option would be to purchase the latest version of Windows which might not run on an old computer. In reality I'd turn to bypassing the activation so I don't have to worry about it.
I think copyright law needs changing. The big recording companies are fighting a loosing battle with DRM, they'll never win. I avoid DRM whenever possible, in fact even when I install a legal version of Windows, I still bypass the activation as a matter of principle.