Moral objections to something that is both 1) pretend and 2) not indicative of the real life effect (slaves were considered property with real value, thus not slaughtered deliberately under normal circumstances) at all are silly. If you're going to morally ban slavery, consider banning the following too since doing so makes equal sense:
- Police State ---> in real life, slaves suffer. In some (most) of these, people DIE.
- Vassalage ---> domination and unfair rule over entire other nations...
- Serfdom ---> well, actually the #1 reason to ban this is because it sucks and you probably should never consider it in ancient starts. Not that serfs had it nice.
- Caste ---> better than slavery, but still forcing people to do things they'd not otherwise choose
- Mercantilism ---> bad economic policy is a bad thing for one's people.
- State Property ---> Decision rights/incentive/reward? NOPE!
- Organized Religion ---> States run on religions do not have a history of treating all their populace kindly or equally
- Theocracy ---> Inquisition! Again, while it would SUCK to be a slave, it sucks even more to be tortured and killed. In fact, being tortured and killed is probably up there with the worst experiences possible.
Why not just start everyone in the bottom row holding flowers for each other
.
From a gameplay standpoint, the degree one suffers from not slaving depends on the map and how many
are available without it. Sometimes it doesn't even make sense to switch (albeit rarely, it happens). Sometimes it is the only competitive source of production available.
But in a game where so many possible actions are immoral, specific hatred on slavery just doesn't make sense period. If you're declaring wars, capturing cities, or running other pop-control civics, there's no excuse for avoiding slavery other than basic roleplay. Of course, not everyone thinks in rational terms. At least in civ nobody really cares if you lose except yourself ultimately, so if you want to avoid civics irrationally because that's more fun go for it.