If you proposed another system in which a recording (not performing!) artist or software publisher gets rewarded proportionally to the value people place on their work, then I might be convinced that copyright should go away.
Kickstarter is interesting and if it worked, it might be able to fulfill this need, but I am not optimistic because it encourages free-riding. If I'm a fan of Stephen King, it does not make sense for me to fund his next book on Kickstarter. The optimal strategy is to wait for others to bear the cost, then consume the work for free (since there's no copyright). I'm not absolutely certain that Kickstarter won't work, but I wouldn't bet on it.
I am not okay with saying "if you're a musician with a family, then you'd better find another job". A recording musician with a family can produce valuable works of art. In an ideal world, he would produce these works and society would reward him. For me the only question is, how to bring about that ideal world? Copyright is closer to that world than free copying.
re: economics: I'm not sure why you're bringing up that economic rule. We are talking about what SHOULD HAPPEN, not what HAPPENS in a free-market economy. I don't think either of us believes the free market equilibrium is always optimal for society. Arguing whether that rule really holds (and BTW I don't think it does in the real world) would serve no purpose here.
re intellectual property: Notice that if there were no IP laws at all, then I could take someone's song and claim I wrote it. Then I could make money by performing it. I mean, once we accept that intellectual property doesn't exist and that the original creator doesn't own his creation in any way, what's to stop me? I think you actually support a middle-ground system, where I am allowed to make a copy of anything and give it to anyone, but I am NOT allowed to profit from it -- only the creator gets to do that. If so, then you support IP to some degree. (Just an observation. No real argument here.)
re changing your mind: Did you change your mind in an Internet discussion or after reading some article? The latter seems much more likely to me. In a public discussion, people never say "Your arguments convinced me and now I believe the opposite of what I said in the beginning." Doing so would mean conceding the other party's intellectual superiority and would make one appear inconsistent. The best you'll get is something like "Okay, there's some merit in what you're saying, but...". Translation: "Alright, you won this one, but don't think you're such a smartass".
The desire to be consistent means the more times you publicly state your point of view, the more invested you become in it. So each subsequent exchange between you and me actually decreases the probability that one of us will change his mind. If either of us changes his mind, it will be long after this public exchange is over. This makes convincing strangers on the Internet a very unrewarding activity, as I will probably never find out if you changed your mind eventually (and vice versa).
You may want to check out this talk by Jaron Lanier. He was not the one who convinced me of the value of copyright, but his book ("You Are Not A Gadget") provides some nice examples and arguments.
http://zocalopublicsquare.org/full_video.php?event_id=359...