Yea? Really? Is this the Cindarella version of slavery then?
No, it's the version of slavery that makes it more palatable for the purposes of a game. In real life, all slavery is bad, and exists whether we like it or not. In a fantasy game, we can outright say that in this world, there is no sex slavery or rape; that it just doesn't happen. Like when Gygax decided that firearms simply couldn't work in D&D and mixing saltpeter, sulfur, and charcoal did nothing but make a stinky smoke.Within Darksun, slaves of the sorcerer king get to slaughter each other in the arena, or be sacrificed for the glory and power of the sorcerer king, but ok thats not as ugly as rape, is it?
Also, imagine, if you will, that the PCs are enslaved. (Let's also imagine the players consented to such a possibility occurring, which is the only way I personally would allow the PC to be enslaved.)
Scenario 1: House slave. The PCs now have access to improvised weapons (such as kitchen knives), can boobytrap the house, poison their owner, or possibly work to undermine their owner in other ways, if they decide to play the long game.
Scenario 2: Arena slave. The PCs now have access to real weapons, other arena slaves who might want revenge, and can possibly even rile the peasant audience into revolting, if they're charismatic enough.
Scenario 3: Forced breeding/sex slave. The PC is likely naked with no access to any weapons or armor or any other support, and no agency, unless they can convince the DM that "has vagina dentata" had always been on their character sheet. Also, this overwhelmingly affects one sex over the other.
And while getting rid of all slavery would change quite a bit of Dark Sun, getting rid of sex slavery wouldn't change anything at all, especially if you make half-dwarfs either a fertile race or no more different than half-elves in terms of how they're made, treated, and the mother's survival chances, which I recall were really low for muls.
Also, there's probably more gamers who have been sexually abused or assaulted than have been actually enslaved, so having non-sex-related slavery is likely to be far less personally upsetting than having sex-related slavery.
I think the phrase here is "duh." However, if half-dwarfs can only be produced by forced breeding, then that means that all PC half-dwarfs are affected by that. If I choose to play an Athasian halfling or elf or human, I can choose my parentage.And just because those two races are highly in demand, e.g. for manual labor, guard and army tasks, free or enslaved, this does not mean that every other classic DS race cannot be enslaved also (or the product of forcebreeding born into slavery , just born to two similar species as enslaved parents eventiually).