Well, why not edit it so you're happy by introducing slavery? Why does it need to be in the book?Again, you're conflating two very different things. It is not an absence of empathy for a product in the world to exist, without malice, and for that product to make reference to a subject that someone might find offensive. I understand that I am not going to convince you of that, but yet, there it is.
If you have an issue with the product, don't buy it. If you do buy it and bring it to a table, and someone tells you that you that they have a problem with it, then don't play it. Or edit it so everyone is comfortable. It's also okay to tell them that the rest of the table wants to play the game the way it is and they are free to find another table that better suits their needs.