So, with the revalations in this chapter, here's my thoughts.
Amasogi exist because desires get out of hand. The owner of the amasogi either hates what happens to the little sister figure in the story and tries to avert it, or has someone in their real life they can't save (or couldn't save), and thus escapes into the book to live out a fantasy (which includes rescuing a substitute for the person they can't help). As far as she (presumably, but can't be sure) is concerned, nobody here is actually REAL, so she doesn't consider what she's doing wrong. They're like video game characters to her, she gets what she wants and nobody actually gets hurt.
Given what we've seen previously where amasogi possessors being unable to give up their desires, she'll probably go full on "I'm an asshole who doesn't care that I sold actual people into slavery", or the amasogi will turn on her and try to force her to choose it over being a decent person. It's hard to say...and I'm honestly not sure I care, either. Not really a fan of this arc, personally.