It isn't just racism and racist stereotypes (DS halflings as "jungle primitives" as one example), but a history of extensive genocides, widespread cannibalism, pervasive oppression and slavery, systematic forced breeding to create the Mul player race...

All wrapped up in a very violent grim-meathook-future milieu.

Any one of these could be fixed without neutering the setting, but probably not all (or even most) of them at once. Even with the most respectful approach to the material, by the time you were done fixing, it just wouldn't be Dark Sun.