I agree, that is why I didn't bring up the possibility of enslavement or colonization. I'd even say the chances are higher of a civ being benign than not when reaching a space faring stage. I base this on mostly nothing.
I do believe an intelligent creature is probably at least mildly curious. Couple that with the likely hood of an advance civ having enough resources to build whatever projects they want, only a small subset of their population would need to be curious enough to make it a reality.