This line of thinking confuses the creative genius with the entrepreneur.
However, that is not to say that they are against copyright. Usually, they like the idea of copyright because morally they dislike the idea of some "greedy capitalist" being able to copy / redistribute and make money using their creation. However, I then ask them whether their status as a musician, and consequently further prospects as a musician and song-writer, would be aided or hindered if others distributed their work for them?
What you express here is a lot of the feelings I have about working on open source software. I write programs because it is something that I enjoy doing, in much the same way you seem to enjoy writing music. I would be upset if the work I did was done without any attribution to me as the author. If some company were to take what I have written and make a profit, I would love to hear about it, and I would like to be respected for my creativity. Drawing form these feelings, the *popular* music industry does well with keeping the name of the "author" with the work itself. Some Joe would not think about claiming a popular song as their own (without a legitimate reason).
There is a lot there to think about, but I must say I identified with what you say as a creative producer of a copyrightable material. And, yes, my day job is as a software engineer, so it is always fun to live both the commercial and hobby sides of my creative outlet. Sometimes they mesh and sometimes they are conflicting. Software development is also going though this sort of "identity crisis", so to speak, that the music industry is. They just seem to be taking different approaches at times.