I read through all the responses thus far. I found a lot of very helpful ideas. To put it simply, I have never used genies in Dark Sun. To be fair, not deliberate on my part. Just never got around to it. I have not played it since high school.
However, I am going over a future possible campaign, and I am putting a lot of mental effort concerning the role of the elemental forces. Athasian genies would put a face and personality on the forces they represent. However, is that a good thing? Are the elementals better completely faceless?
I would say I do not think they would represent a united front in any way. Imagine one earth genie wanting to build a mountain where another wants to build a ravine.
I do lean towards them having some kind of broken or fallen culture. Mere shadows of what they once were.