For what it's worth, I've never liked the presentation of the Vulkoori. The Qaltiar were my attempt to broaden the scope of the Vulkoori into a civilization that used primal magic as its base—focusing on the point that a civilization that uses a different sort of magic as its foundation -- primal, psionic, divine -- will be different than one based on arcane.
The Vulkoori follow a different path, but that doesn't make them more "savage" than the Sulatar or the people of Stormreach; it means they have mastered a form of science those other cultures don't understand.
And to the lizardfolk, I'd argue that the Poison Dusk aren't demon WORSHIPPERS; they are victims of demonic influence.
I agree that from a player perspective it may be different, but it's not a case of a savage culture, it's a case of supernatural influence. While the Cold Sun I focus on as being entirely alien.
I see a similar situation with the Talenta, we've just never gone into them with enough depth to see the virtues of their system and the tools they have access to through their interaction with spirits.
To me, most of the civilizations that appear "primitive" in Eberron are employing systems the "civilized" people don't understand; it's not that they aren't clever enough to grasp the Galifar way of life, it's that the tools they've developed are better suited to their region and way of life.
And honestly, [user], I could imagine doing a deep drow dive some day. Qaltiar, Umbragen, and Sulatar are dramatically different, and the Qabalrin could get squeezed in there.(edited)
But I agree that the Vulkoori—especially as the default drow everyone knows—are problematic.