The response to TPB here on Slashdot seems overwhelmingly positive, so maybe I've been missing something. I'm honestly curious. As a commercial software developer who works very hard and doesn't want to see my work made available for free, why would I approve of what TPB are doing? I mean, if people don't pay for the apps I make, then my kids don't eat (well, or I have to go find something else to do that I'd probably enjoy less).
I am a software developer by profession - my livelihood comes from copyright at the moment.
Copyright exists to "promote the progress of science and the useful arts" - I would make the case that it no longer does so. A much shorter copyright term would still provide incentive to create, while allowing things to fall in the public domain - where they are free to be modified, improved, built on by others.
My personal reason for completely opposing copyright is that it is fundamentally out of touch with reality. I believe in regulating markets (well, almost anything) only when it's necessary to protect people from each other. Value comes from demand and scarcity - something that is plentiful is not really worth much.
Software has value, yes, but it is the act of creation that is scarce - not the act of copying. Anyone can copy, and many will.
Barring government intervention to the contrary, the "cost" of acquiring a copy naturally tends towards zero - increased competition drives it down towards the cost to make one.
Everything we do is done on the backs of those before us. When I observe someone fix a car, efficiently clean a room, prepare a meal, paint, sing - I am looking to see how I can improve what I do - by copying them. They retain their knowledge, but I benefit from duplicating. From a utilitarian standpoint, the cost to an individual of reduced scarcity is far outweighed by the benefits to society of free exchange of knowledge, or skill, of culture.
Alternatively, from the libertarian standpoint, it is unethical to interfere in the affairs of others - they are depriving you of nothing in the first place. Your "right" to earn money from your software is a government-enforced artificial monopoly - it is out of touch with fundamental realities. When they copy your software, they are not depriving you of anything, other than a government-granted right to control the making and distribution of copies. The government is (supposedly) an agent of the people, and is limited by the Constitution to actions specifically authorized.
Right now, software is often produced at a loss, then copyright is used to allow them split the cost up among the users. Put simply, it's a loss leader, with the revenue model protected by law. Why should software get special protection when other loss leaders (CueCat, iOpener, etc.) do not? Their designers are free to take the risk, and free to earn their rewards, if any, on their own merits.
Would abolishment of copyright do away with the creation of software? Of course not, but it would certainly change things. The need for software still exists.
DRM would have it's place, and would be much more popular than it currently is. Personally I hate it, but it is an ethical approach - the author is free to write and protect his software as he sees fit, and I am free to modify and use it as I can manage. DRM raises the cost of making and acquiring copies - it can preserve value in scarcity without the need for government intervention.
As a company, we commission software all the time. Often, we will go in with other companies to have something created. For things that are not our core business, we have no problem with giving it away - we have nothing to gain from keeping (for example) a CRM scarce, and nothing to lose by giving it away to the world. Software would still exist, it would just feature a different compensation model that reflects real scarcity rather than artificial government-granted monopolies.