Slavery is very common in the medieval ages and in reality, up until about a Century ago.. there's nothing to punish for doing something legal.
sure, it's against human rights.. but I doubt that even exists.
@Glomoro
True, and a most logical explanation.
Tho he must have seen it as normal in this world too since he referred to himself as a Corporate Slave, thus making him accommodated to the idea even with the change of culture.