Keeping a single free license in the free community is better for the dynamic of the community.
Software, music and documentation, articles, ..., are all different kind of works, and need different kind of protections. Applying a hammer when you wish to screw in a screw, is well... Silly, to say the least. You don't need to be change my article about who much I love feries, to say that I don't love them. Fo functional works (software, for example) one needs the right for modification, fo non-functional (non-technical written works) one doesn't. Music, and a novel, are quite similar, and a simple `verbatim copying allowed' is quite satisifactory for such works. A manual, or a program, is where you need more freedom since it is useful to change a manual, or a program. But a manual is very different from a program, so a manual needs to define a different set of freedoms.
Keeping a single license, that is applied to everything, will only hurt the community in the long run.
Cheers.