Condoning slavery with such an argument is something REAL people do today about REAL slavery (and not just in the US). Using these very same arguments, like "They deserve it", "they are criminals anyway", "they are treated better than the poor or homeless." all of these things shouldn't be taken...
@diogenes thanks for the spoiler because I was going to drop this.
It's disheartening how many of these isekai are incorporating slavery into the core plot, without any good reason. Shield Hero, has a good reason I don't know why they stay slaves but it was a good reason, so I still read it. I...