I mean, that you don't agree doesn't mean that it's not typically regarded as such. Specifically, WotC is a part of Hasbro, a large publicly-traded corporation. Such companies are inherently risk-averse. D&D is undergoing a true renaissance, becoming bigger than it ever was. It has done that without any attempt to court controversy or address "mature themes" and indeed, only 3.XE ever even really flirted with that, and that only briefly. There is no logical reason for the company to divert into anything which is even potentially risky at this point. "Mature themes" or "controversial material" is not part of the WotC brand, nor part of the D&D brand. On the direct contrary, in fact.
It absolutely could be, but if you expect a large corporation specifically known for playing it relatively safe, whose product is currently succeeding in a big way, to suddenly decide "Hey now is the time to push risky stuff no-one is particularly asking for and which the setting doesn't need!", then I'd suggest you need to adjust your expectations quite a lot.
If you're expecting some 3PP known for risky material to do it, then that's more reasonable.
Re: chattel slavery, the Romans had chattel slavery in the sense you describe as well as debt slavery and indentured servitude and so on. The big difference was that generally the Romans didn't "breed" slaves or maintain long-term slave populations in extremely poor conditions, and Roman culture had certain broad expectations about how slaves were to be treated, which were better than those of the South (or indeed some other ancient societies) - they weren't typically written into law until the 100s or later IIRC (but then they gradually got actual rights and everything). It was still horrific of course but lacking the breeding and racial aspects and I would argue with lower levels of inhumanity overall (and also relatively smaller populations - at the absolute peak Rome might have had 40% slaves in certain agricultural regions, whereas in places like Haiti it was more like 85% of the population were slaves). And unfortunately the Muls in Dark Sun bring in both the breeding and racial aspects pretty seriously.
But I'm maundering on, sorry.
Point is I think the "necessary" alterations to "make safe" Dark Sun wouldn't rob it of an inherent character and might actually seem smaller than the ghastly 2nd boxed set in 2E, let alone the 4E changes. I'd be fine with much bigger changes personally, so long as certain key aspects are kept (psionics is not in fact one of them for me, but if it's ditched, you'd need to do a hell of a lot more with magic to replace it).
EDIT - As an aside, I believe if D&D keeps succeeding, there may eventually be a demand for "mature" settings (moreso than Ravenloft) that WotC wants to meet, as new kids grow up playing the FR or whatever and feel it's a bit too sanitized and they want something edgier for their late teens and twenties, but that's not likely to happen for a few years yet I'd suggest, so probably would be a 6E thing.
Nice response - and I don't think we're that far apart. I think the main point of difference is that I don't see a problem with depicting, say, Dark Sun-style slaves. I'm not saying that
someone won't find it problematic, but someone will find almost anything problematic. And then, where to draw the line? I mean, D&D is a game in which violence is a central component and could be seen as advocating the view that violence is a good way to solve conflict. Should violence be removed?
Of course not. D&D is a game of make-believe, and set in worlds in which violence is, indeed, a major aspect of daily life - or at least the life of an adventurer!
Again, it isn't a statement of advocacy for anything in particular, except perhaps that "slavery is bad." But it is also a matter of the context of the fantasy world itself, the set-up. So I think the question is not (or should not be) whether depicting slavery in a fantasy world is problematic--it isn't, no more so than depicting any number of other things that aren't nice--but whether or not, as you say, WotC wants to publish things with more mature themes.
But they already do. The books are filled with stuff that a younger child might find scary or at least has not been exposed to before.
A point of clarification: by "mature" I don't mean
Book of Vile Darkness or
Erotic Fantasy. I'm just talking about stuff that is mostly already in D&D, that is beyond the typical "PG" fare.
And I do, of course, realize that there are different ranges of response - of what is and is not problematic. Actually, that's part of my point. I just think that WotC needs to find a middle-ground between extreme views on either side, and one way to do that is double-down on the idea that "fantasy is fantasy," and ideas explored in settings like Dark Sun aren't statements of advocacy for such things as slavery and cannibalism. I mean, it kind of should go without saying.
p.s. No need to apologize for maundering, aka geeking out on interesting topics! And hey, you just taught me a new word (I thought you mispelled
meandering).