Unobtanium is a good name because by the end of the movie they don’t obtain it.

I like the name unobtainium - it holds within its name the idea that the cycle of extraction and exploitation will never be complete

Unobtainium has a long and proud history in sci-fi. Cameron using it was just a nod to that. Basically it’s a Mcguffin material, that just happens to do exactly what the plot needs it to.

It’s a call back to the cold war, or earlier. Famously when the CiA was trying to make the SR-71 blackbird spy plane they needed titanium for the airframe, but the ussr produced almost all the world’s titanium and wasn’t going to sell it to them, hence “unobtainium”. So they built hundreds of shell companies to buy up small amounts of titanium and smuggle them back to the kingdom of nightmares… i mean America, and build their spy plane. It only sounds dumb if you don’t know the reference.