It might well help to understand where the term 'Western' started.
Did it emanate from the British idea of "The Wild West' which was representative of the US pre 1900 generally and which presented as cowboys, indians, prospectors, sheriffs, Wells Fargo, the cavalry, forts, tepees,wigwams, Pinkertons agency, wincheters, colts, etc etc?
I have no idea personally but that's my guess.