My main problem is that the word primitive is almost always used in a derogatory way.
That's just your perspective, I don't hear it being used frequently at all, and even when it's used is not usually derogative, and in the few "derogative" instances I've heard it, it's often used jokingly and mostly thinking about pop culture's cavemen rather than the actual primitive humans, making fun of that representation rather than the historical group.
Calling someone primitive is never a compliment.
Why would it be? Is it automatically an insult if it's not praise?
And also calling civilizations primitive was a strategy used by a lot of colonizing forces to excuse their horrendous actions by simply saying they're just a bunch of primitive Savages so it's fine for us to do this.
And why tf should we care in a world where that strategy is no longer used? You are even talking about this in a space where no one is using the word Primitive in a derogative way and understand they weren't stupid. As I said, you are the only one here treating "Primitive" as to be equal to "Stupid" or "Savage".
Also, I even really like the word primitive, I even sometimes use it to explain specific emotions or reactions, meaning to portray them as something deep within our nature, the very foundations of our being and from where everything else is born. It's probably easier for me since in Spanish "primitive" is written "primitivo" which always reminded me of "primero" which is "first" so "Primitive Humans" only means "The very First Humans" to me. And as I said, that's always going to be relative to our current standing point.