The only valid argument you've said is that people create art for reasons other than making money. Which is of course partially true. But obviously, to a lesser extent. I'm sure many people on HN would still program without getting paid for it, but there should be no doubt in a reasonable person's mind that overall less good software will be created, and many of those individual people, artists though they are, will create less software because of lack of time due to having a day job.
There is also a large amount of BSD-style licensed software out there, that won't go away if copyright goes away, because it's already free.
Of course a part of the software industry is about producing proprietary software for sale, but that's a small part of the industry as a whole, and I'm sure some of those companies can find ways to survive in a world without software copyright.
So a small part of the programming workforce might be out of jobs, and an even smaller part of those might then in turn not be creating good software, so the total amount of good software produced might go down. But that's a lot of mights and ifs and buts. Perhaps the opposite is true, perhaps removing software copyright might lead to more good software being created, since everyone is free to re-use and re-mix and build upon all existing software, not just that which is currently OSS-licensed?
Copyright is automatic at the point of creation for a work that qualifies under the Berne Convention; it does not have a distribution requirement.
>a large amount of BSD-style licensed software out there, that won't go away if copyright goes away //
Actually it will. All open-source licenses rely on the person applying the license to hold the copyright, copyright is what gives them the right to demand that the license terms be adhered too.
Personally I would not like to see copyright disappear completely as I think this would be a disaster for those creating 'works'. A reasonable term is what's required IMO; possibly with an extended term of moral rights.
http://en.wikipedia.org/wiki/Shakespeare%27s_plays#Source_ma...
http://www.shakespeare-w.com/english/shakespeare/source.html
However we could plausibly find ourselves living in a world without these multinational corporations.