I recall someone at Wizards of the Coast (could have been Ray Winninger, but I can't be hedgehogged to check) saying something along the lines of "Only about one project in three we start working on make it to publication." I have a fairly strong suspicion that 5e Dark Sun was a casualty of this process relatively early in the 5e publication history. Something along the lines of:I kind of suspect this might be the most important reason Dark Sun hasn't made a comeback.
1. Dark Sun is one of our more popular older settings, so maybe we should do that.
2. Plus, that would give us a good "in" for psionics, and we said we wouldn't do settings unless there was something mechanically different about them. (Note: this seems not to be a criterion anymore, but it was mentioned back in the day in the context of Greyhawk being a setting using some more old-schoolish rules.)
3. OK, Bob, you start writing a treatment for the setting material and lore and such. Mike, you start working on psionics.
4. Oh great, you have the skeleton of a psionics system. Let's put it out in Unearthed Arcana.
5. Dang, I guess the fans didn't like that one. Let's try again.
6. Nope, that didn't work out either.
7. Dang, this edition sure blew up. Lots of young fans. Maybe we should take a look at our standards for publication.
8. Bob, what's that you got there? The Dark Sun treatment I asked you to write? Hmm... hmm... yeah, this isn't going to fly in the New World Order.
9. Tell you what, between not being able to get psionics going and sensitivity stuff, let's just drop this Dark Sun idea for the time being. More trouble than it's worth.
Slavery was definitely treated as an evil thing, but as an entrenched one. The adventure included in the original boxed set starts the PCs out as slaves being transported across the desert. The caravan gets attacked by elf raiders, which leads to the PCs being "freed"... right out in the middle of the desert and barely being able to get a waterskin each from the wreck.From my (limited) knowledge of Dark Sun--which does not include anything from the novels or adventures--slavery was just treated as another part of the setting, not as an evil to be fought. I think that's the actual big issue with the setting. There's little the PCs can do about it, especially at early levels.
Then you have the first separate adventure, Freedom, where the PCs are enslaved and forced to work on the Ziggurat in Tyr. The picture painted of slavery is not a pretty one. And at the culmination of the adventure, the former king of Tyr is killed (by NPCs), and slavery is abolished in Tyr. And this is the point where it gets a little complicated. Later material, like the Tyr sourcebook, shows that while this is overall good, it is not without its problems. For one thing, you now have a large destitute underclass of former slaves, which is a destabilizing influence. You also have lots of resources (farmland, the iron mines) that are being abandoned because of the lack of workers (and the nobles don't really have the resources to employ their former slaves). You also have other city-states who see what happened in Tyr, and decide that they will not be having any of that, leading to a short-lived war between Tyr and the closest city-state, Urik (with the result being that Tyr defeats Urik in the field, but when they try to follow their success up and attack Urik itself in order to free their slaves as well, Tyr gets soundly routed). So the abolition of slavery is described as a positive, with an asterisk.
It's a well-known fact that Internet trolls actually get stronger when exposed to flames.C'mon, you've certainly been playing enough D&D by this point to know to bring along at least some form of fire or acid damage for situations like this.