I don’t think that most of these writers are arriving at their societies by probabilistic extrapolation. Rather, they are just writing what they want their societies to have.
Those aren’t the only possibilities—much more likely is the Rule of Cool. Wielding a sword is cooler than wielding a gun, and swordfights are more interesting than gunfights.
Those aren’t the only possibilities—much more likely is the Rule of Cool. Wielding a sword is cooler than wielding a gun, and swordfights are more interesting than gunfights.