zlacker

And authors don't have any natural right to prevent people from copying their books.

And yet, we have decided that society is better off when authors can make money off their work.

>>vkou+(OP)
That's exactly OP's point: the output to society is what matters, not the simple existence of a career. It can definitely be argued that society will be the worse because SD replaces artists, but we shouldn't assume a priori that eliminating a specific job is a bad thing.