I actually like the setting, I just think it doesn't fit with the D&D ruleset at all.
Play it in Savage Worlds and I'll be very interested
Yeah, the setting is amazing, but the AD&D ruleset didn't work for it terribly well. Well, they didn't design psionics to properly mesh, rather. I am in the middle of making my own ruleset for 5E psionics, and getting close to done at this point. I want psionics to be both different, but on par with the other subsystems. There's a reason I've played Dark Sun in HERO System (soooo simple to do) and in FATE (omg, does that system play to the narrative-oriented strengths of a sword and sorcery apocalyptic setting) more than I with the D&D rule set. Although 4E worked pretty well for it with minimal tweaking.
I am definitely curious why some people seem to have such a horrible experience micromanaging resources like food and water. That was only ever important in the many, many DS campaigns I've played in or run, when it is story-appropriate. Kind of like the rules for being corrupted enough to stay trapped in a domain in Ravenloft...
Which is pretty much the same as every other campaign? Only without having to keep track of lots and lots of other resources, like consumable magic items, regular magic items, etc. Because those are barely present.
Then again, I'm rather confused about the multiple comparisons of Planescape to the World of Darkness setting. Is that because Sigil happens to have a core group of named factions? Because that is pretty much the only thing remotely similar between the two settings. Like, at all. The art, the environs, the scope, the way the various factions interact with one another (and with the Lady), etc? All extremely different.
All that being said, it is pretty fascinating how resilient it is in this contest, considering how many downvotes it's gotten. It's gotten almost twice the number of upvotes as the next highest setting (Eberron).