Thank you all for your responses.
I asked because I bristle when people attempt to dilute and soften what happened when my mother was murdered. I use the word "murdered" or "killed", because the murderer doesn't get to have simply officiated a "passing". My best friend told me she says that to be kind to me. I just wanted to understand why she feels that cushioning language is kind. I still don't like the euphemistim, but I understand that it's pervasive, and meant to be "good manners". TYFYC