First, I never brought up anything about supporting designers of furniture or cars. You did. But, since you did, I'll bite. CDs are certainly not the same as cars or furniture. People buy cars and furniture because they have material and functional value. You buy a car for its transportation function and furniture to sit on. The only function of a CD is as a table coaster, a mirror, or something you hang from your rearview mirror. A car has intrinsic value; it's made of parts that cost money, one could sell them if they wish. A CD has neglible material value; it's made of plastic and it likely costs about a quarter to make. So why does it cost over $10? Because it contains intellectual property. That's the value of it, not the physical CD. This is proven by digital sales; they cost nearly as much as physical CDs themselves. It is the data on the CD that one pays for.
By your logic ("artists have gotten compensated legally by their original purchase"), you can go buy software, then go around to all your friend's houses and install the software on their computers. The artist (software engineer, in this case) was already compensated when you initially bought the software-containing disc, right? Is it alright if I go to my friend's house and rip 100 of his CDs on to my portable hard drive? He already payed all the royalties and such, right?
As for the Garth Brooks case, look up the definition of a straw man argument and get back to me on that one. I never said buying or selling used CDs was illegal, just an unfair practice and an ethical gray area. But, as you point out, you have no emotional attachments.
