> the main immoral thing about theft is that it deprives someone of what they used to have
You should have just stopped there. That "or takes the place of a sale" rider is a very recent invention. You know what else takes the place of a sale? Spending your time doing anything else and ignoring the fact that the work even exists. If I could have paid to listen to a song from artist A and instead I listen to a song from artist B (free or paid, but we'll assume it was with permission either way) then that "takes the place of a sale" for artist A, but there's absolutely nothing immoral about choosing to listen to artist B's song instead. Or reading a book, or sleeping, or whatever. You could even write your own songs and give them away for free, directly competing with artist A and taking the place of many sales, and there still wouldn't be anything immoral about that. Artist A was never guaranteed sales, so they haven't lost anything simply by not making a sale. They still have their copy of the work, so they have not in fact been deprived of anything.
Complaints about piracy always read to me as: "You aren't complying with this monopoly which was promised to us in a rather one-sided deal with a third party (government) which (unilaterally) claims to represent you. If you don't shape up—or even if you do—we intend to sue you for everything you own in courts run by our beneficiaries and otherwise do whatever we can to ruin your life, just on general principles and not because we suffered any actual damages." And yet they have the audacity to pretend to claim the moral high ground…
You should have just stopped there. That "or takes the place of a sale" rider is a very recent invention. You know what else takes the place of a sale? Spending your time doing anything else and ignoring the fact that the work even exists. If I could have paid to listen to a song from artist A and instead I listen to a song from artist B (free or paid, but we'll assume it was with permission either way) then that "takes the place of a sale" for artist A, but there's absolutely nothing immoral about choosing to listen to artist B's song instead. Or reading a book, or sleeping, or whatever. You could even write your own songs and give them away for free, directly competing with artist A and taking the place of many sales, and there still wouldn't be anything immoral about that. Artist A was never guaranteed sales, so they haven't lost anything simply by not making a sale. They still have their copy of the work, so they have not in fact been deprived of anything.
Complaints about piracy always read to me as: "You aren't complying with this monopoly which was promised to us in a rather one-sided deal with a third party (government) which (unilaterally) claims to represent you. If you don't shape up—or even if you do—we intend to sue you for everything you own in courts run by our beneficiaries and otherwise do whatever we can to ruin your life, just on general principles and not because we suffered any actual damages." And yet they have the audacity to pretend to claim the moral high ground…