> Without copyright, how would The Beatles ever have become the celebrities in the first place?
They were overnight celebrities. Too fast to ascribe it to copyright. And radio stations played their music for free. A cult-like following immediately grew up around them. That wouldn't happen with a clone. Look at all the fan magazines at the time printing every detail about the Beatles - a clone would be totally ignored. The Beatles' success cannot be placed on the lyrics and arrangement, it's far more than that.
> not on how new work will be created
I work on open source full time. All the collaborators on D also contribute their work to the Boost license.
> Are you counting on passionate independently wealthy hobbyists to create everything copyable for free?
Microsoft (among others) open sourced much of its software. Lots of companies make their software available for free. Open source is highly successful, does not need copyright, and the evidence for it is overwhelming.
> Almost all successful open source software is protected by copyright and license terms that restrict its use.
My work is Boost licensed and copyrighted, simply because public domain is not recognized in many countries. The Boost license is the least restrictive of all the licenses.