Yes, people write for other reasons (e.g., self-promotion). But that does not account for "most authors" I would actually want to read.
I'm not against copyright being different, especially for things that are written as work-for-hire. But that's a fight with Disney. Good luck.
No, it was established to make investing in printing presses more profitable, which is why the rights initially attached to printers. Authors as the locus of rights were a later change.
Yes, wealthy aristocrats wrote whatever they wanted and less wealthy authors wrote what they got paid to write by their wealthy aristocrat patrons.
Copyright and the publishing industry changed that to make it possible to live by writing for ordinary people.
Its disgustingly dishonest to appeal for "poor" authors where casual glance immediately proves that modern IP law exceedingly profits only a few massive corporations and their shareholders.
People write for reasons other than money from the sales of the book. This accounts for most authors, who aren't famous enough to negotiate a great deal with a publisher.
And we don't need to abolish copyright outright. Just require that it is continually published at a steady or decreasing price, or it becomes public domain. And put works in the public domain a little sooner.