Since I first saw Dark Sun, I always felt that it too easily dismissed some of the common "bad guy" humanoids existing in that world. Yeah, they tossed in background pieces about them being exterminated-- but are you really telling me it would be easier to exterminate Orcs than it is to exterminate Dwarfs or Elves? I feel like they felt compelled to keep the races in the PHB alive in the world despite if it made any sense.
Now that more development has been done on exactly what an Orc is and what its specialties are, I feel like Orcs would have had a much easier time adapting to the scant food and lack of water the world of Dark Sun presents. Its just now all that difficult for me to imagine these desert dwelling Orcs with sandy orange skin who might live primarily on the weeds, but are all too happy to bury themselves in the sand and ambush those who are unlucky enough to find themselves out traveling in the desert to kill and cannibalize them. And also to be prized as good, strong slaves that don't require much upkeep, but tend to be a bit lazy unless whipped into shape.
And you have this whole evil, brutal dictatorship as your core civilization where survival of the fittest reigns supreme and might makes right? It seems custom tailored to include the more modern concept of Hobgoblins as primary enforcers of this system whether or not they ever get accepted into any roles of meaningful power or influence.
But, at the time these concepts weren't particularly well developed and were different bags of hit points to pop in order to extract the XP and gold. So I guess they thought that having different "monsters" would make the setting unique... but still didn't have the guts to eject the elf, the halfling and the dwarf which all feel far more wildly out of place in the setting than Orcs or Hobgoblins would.
