Part 1: I could convert to your opinion if you can find one hairdresser who
affirms that her business is harmed because she cannot modify the music she
plays in her salon (or who modifies free music to specifically please her
clients). If you cannot, here is the fundamental difference between the
music and the scheduling program, which may have a bug the hair dresser wants
fixed, maybe a missing feature to handle the specifics of her business, maybe
malware, etc. Only artists wants to modify the artistic works. It is not
about defining "classes of people": the hairdresser may be a music artist
too. But she is not acting as a music artist when she is running her
haircutting business.
Part 2: I do not get your point. Artists who would take advantage of a
five-year monopoly (on commercial exploitation and/or modification) do not
withdraw any money from those who choose not to accept such an advantage...
which is is not such an advantage today because the money paid for culture
(e.g., the tax the hairdresser pays today to play music in her salon) do not
go to artists unless they are superstars. But that is a separate issue.
I agree that high-quality artistic works can be, or even often are,
derivatives. That is why copyright should never go in the way of creating
original works (its objective!), including mash-ups or remixes, even if they
reuse works published today. That is also why it is bad to have a
never-ending copyright, basically the current situation in some countries
(such as the USA and their Mickey Mouse Protection Act). But I do not see
any emergency in letting anybody do small variations of existing works, or,
more commonly, reuse the work unaltered in a commercial way. Is it that bad
for society to have those possibilities delayed by five years? Again, I do
not think such a monopoly harms the freedoms of the
readers/listeners/spectators/hairdresser, contrary to the freedoms of the
users of a functional work. In other words, I consider developers of
proprietary software evil but I do not consider an artist is evil if she take
advantage of a five-year monopoly (on commercial exploitation and/or
modification) on its work, after its publication.
Your "Mimi and Eunice" example has nothing to do with copyright. A third
author drawing new episodes could raise a trademark issue (if Nina Paley
would manage to get a trademark on her characters) or a patent issue (if
patents on Arts would be allowed, what would be a terrible idea) but these
are completely different topics.