Barbarian Tribe: The term “Interstellar League of Tribal Chiefdoms” was not intended as a compliment, nor was it given with any degree of irony.

Also, given their views on, say, the sanctity of contracts, the personal defects of people with authoritarian tendencies and the systems they produce, etc., even before we bring in issues like entropism and cacophilia, the “barbarian” moniker is quite widely applied.  But very specifically has little to do with degree of technological advancement, even if it might apply to lack of desire for such advancement.