The history of every language on earth is full of cases where the original meaning of a word is aggrandized and expands to designate more objects than the original. This has happened to the English word ‘guy’ deriving from the name of Guy Fawkes (as in the “Guy Fawkes Rebellion” of 1605).
Nowadays ‘guy’ in American English can refer not just to males but to females as well as animals. Also, where once it was used to refer to younger males, it can now refer to persons regardless of age, hence to geriatrics of both sexes. This was demonstrated for the umpteenth time to Y-H-B when I heard the bartender at a local eatery in Manchester Center, Vermont, repeatedly address customers of an advanced age as “guys.” Highly inappropriate in my opinion, but what’s a purist to do?