[triplefox]

Or if you want a strictly economic explanation: The law is a cosmetic blemish upon what could be a top-to-bottom free system.

The high level would be original free software and media - tools and inspiration.

The medium level is derivatives; things made using the tools and media built upon other media.

The low level is the consumer level, where the best things are filtered and distributed to the public.

The system takes the lowest-cost option at each step: remixing material and building on open source is easier than starting from scratch. Digital distribution is easier than physical distribution.

But it is entirely dependent upon the source material being permissive-use. When it isn't, derivatives become illegal material, and people will subsequently choose not to make value-added derivatives because any profit motive that would have existed is gone; settlement and legal fees are likely to wipe out any gains.

This doesn't affect the consumers of media, however, because consumers are largely anonymous and hard to target by the legal system. Thus you get widespread piracy, but few derivatives.