If books, movies, music were taxed like property at an assessed value this would in my mind be fair. The argument against this would be the rightsholders would say they already paid taxes on the profits. But owners of a property that generates an income pay both property and income tax so it seems right. And just like so called real property where people let their property be repossessed to pay back taxes, unprofitable works would be let go into the public domain.
Of course this would lead to perpetual copyright for profitable works, but I doubt it would stifle creativity by making the books unavailable, as no one sane would price themselves completely out of the market.
As an aside, the argument about stifling creativity does not hold much water for me. Shakespeare, Dante Alighieri, even Charles Dickens did not have millions of free books to stimulate their creativity and they along with thousands of others seemed to manage okay.
Taxing an intellectual property like physical property is probably not going to happen as one can only imagine what Disney et. al, would have to say
but it might be nice if it happened and kept the tax collectors so busy that they forget I exist.
Helen