I think copyright is a valid incentive.
I don't think reading books (whether by human or by machine) is copyright infringement.
I think that attaining books that are still under copyright by downloading a pirate torrent is wrong.
I think a machine reading those books by borrowing them from a public library is fine.
I think copyright holders restricting their books from being in a public library is just as wrong as downloading a pirated copy.
I think deliberately reproducing a copyrighted book is wrong, but the infringement is by the person who did that, not by the person who built a tool which can incidentally be used for that.