Can we come up with a different archetypal bad/clueless user than "grandma"? My son's grandma manned a crew-served grenade launcher and ran radio intercept equipment in the Army and now owns her own database consulting company. The way it's used brings to mind a crooked, old, white haired woman who spent her life in the kitchen. That's increasingly not anyone's grandma. Using the name in this way is both sexist and ageist.
Stop using "grandma" as a stereotype. World War Two spectacularly proved that women were neither clueless nor technologically incompetent; and it's fast approaching a century since then.