This strikes me as a bit ironic, if you're serious, as you list your current work as covering the entirety of the Beatles discography. Are you paying them for the rights?
I actually think it's ironic for precisely that reason. Similar to covering music, there is a legal precedent for making books available in public libraries - though most cover artists don't pay the royalties, and in this case this online library is not paying the GP. In the case that GP did in fact pay the fee, I rescind my criticism.
My understanding is that libraries do pay fees to stock books, some of which goes back to the original author. Anna's Archive does not pay anything back to the authors.
I think GP's criticism is valid. The toplevel poster is creating work that leverages the creativity of others. Regardless of whether or not he's paid a fee to do so, it's still funny to see the indignation about sharing, when the person's current project involves using the work of others.
There is both a qualitative and quantitative difference between covering/remixing the art of others, vs. just putting the original up for ~~sale~~ free.