I've spoken before that some classes are diagetic (they represent a type of person in the world) and some are nondiagetic (they are blanket terms for a lot of different types of people). Paladin, druid, monk, bard, those tend towards diagetic (the character would consider themselves members of that group in fiction) while fighter, rogue and sorcerer are nondiagetic (people wouldn't address themselves with those titles, at least not how the game defines them.) Thus, you might have Aragorn the Ranger and Gandalf the Wizard address themselves as such, but Gimli the Fighter or Bilbo the Rogue aren't.
What I think is happening is that people want all classes to be diagetic and thus be like titles or professions in the fiction of the world, while others want classes to be nondiagetic meta-parcels of class features that can be flavored however they want. Bob the Fighter might be a knight, a soldier or a gladiator, but Susie the druid is always a priestess of nature.