Interestingly Narf and Aiken you are both disagreeing with me, but you seem to be making arguments that are exactly opposite of one another.
Narf you say that you aren't buying a physical object, but a license. And the license allows you to make backup copies. This is correct in many (most?) cases and I have no disagreement to it. However, the original point being made was that the content providers seem to be moving towards eliminating that as a feature of the licensing. And there are the myriad shades of grey now involving what does or does not constitute fair use under the current licenses.
Aiken, you seem to be taking the opposite side of the argument. Going so far as to call it a "commodity" and saying you have the right to do with it whatever you want, even destroying it. This is true of the CD the software comes on of course, but is it true of the software on the CD? DO you have the right to copy it and then destoy the original?
It's not a commodity really is it? If you destroy a shirt you bought you can't use the backup copy of the shirt. In that case you aren't really buying the shirt as much as you are buying the labor, materials and skills neccesary to make the shirt for you. If you destroy the shirt and make your own, you aren't doing anything wrong. But that will take time and effort on yoru part.
But if you copy software, you aren't doing the same thing as making your own software. There is no labor, no skill invested on your part. You are pressing a button and making a copy. So it's clearly not the same thing as every other product and commodity you might purchase.
Tesco, your point isn't really a legal one but a technical issue. I didn't want you to think I was ignoring you, but I don't see how it applies to the question.