::::::: I will not file an RM here yet (being tired and bored of discussions where the same pack of obstinate naysayers pop in with irrational claims), but the reality of this term's negative and derogatory origins was noted by John Swanton, quoted here on the Canadian genealogy website in his article on this people - "From the Siksika (Blackfoot) words sa arsi, "not good."  Somewhere else on the same or similar site I found a more explicit statement that this name is considered derisive/derogatory, I'll return with it once I find it.