I'm kind of annoyed with the way Wizards of the Coast has treated Dark Sun

Honestly, I can go for some hopecore/hopepunk. Does seem a lot more interesting than just everything sucks so you have to fold into what the world wants/says.

My biggest issue is more that the Dark Sun setting seems to be completely forgotten. I always had fondness for the setting myself, but it seemed like a flash in the pan type of deal.

Quote from BalefulBeanie >>

My biggest issue is more that the Dark Sun settings is that it seems to be completely forgotten. I always had fondness for the setting myself, but it seemed like a flash in the pan type of deal.

That's usually how it goes with something that breaks so far from the main dynamics. Setting aside the myriad dystopian social issues the setting entailed, there's still punishing wizard builds, outright nixing clerics and paladins, and scrapping metal weapons and armor in favor of far inferior improvised ones. Makes for an interesting and engaging change of pace for some, but for a lot of others it's just "D&D with some of the fun stuff removed and new hard stuff added". Doesn't really lend itself to mass market appeal, which is D&D's bread and butter.

I recall it selling pretty well when it was released. It wasn't exactly unpopular or niche. I also recall that it was stated that  the darker themes that were present in the world that got in the way of any sort of reintroduction. 

If it aint your thing it aint, that's fine, but I'm pretty confident if it were picked up again, it'd be pretty popular. It's a pretty compelling world. 

Some of the themes in there are politically toxic in today's environment.  WOTC isn't going to touch something with slavery for example, with a 10 foot pole.  I don't see anything resembling the original darksun to fly.

Don't the drow have slaves still or was it retconned or something?

The presence of slavery somewhere in the setting isn’t a breaking point, provided it’s clearly categorized as as an antagonist/villain flag. Which could be an issue for Dark Sun, as it seems likely the setting would make it more normalized to play into the grimdark post-apocalypse vibe.

I think maybe the Dark Sun setting's failure to thrive was not so much a result of the content of that setting, but of the time in which it was presented. Dark Sun was first introduced in 1991, when TSR was in the middle of a transition from AD&D to AD&D 2nd Edition. The new edition was an attempt to clean up the image of the game, which a drastic reduction in the use of demonic or sexually suggestive artwork and narrative. But those are the very themes that the Dark Sun setting would thrive upon. The 90's also experienced D&D's first lull in business. The game had grown swiftly in the 70's, exploded in the 80's, but by the 90's it was starting to settle in to a pace. It was still growing, but not at the explosive rates of earlier years. So the company saw revenue leveling out, while still trying to increase output. Something had to give. And that's when the legal battles between several of the founders began, then the bankruptcy scare and the buyout by WotC. And the copyright battles continued even after 3rd edition and 3.5 came out. So the new company made the wise business decision to focus their efforts on only those game properties that could most reasonably be expected to guarantee a return on their investment, and sadly the Dark Sun setting was not that. 

Dark Sun is a niche within a niche. I loved it. I still love it. But I harbor no illusions that WotC or now Hasbro will ever dare to invest in it further. So instead, I've been working on developing my own homebrew version to stick into a remote part of my own campaign world. It's "D&D meets Mad Max". I think that's the most sensible path forward for now.