First off, I have really enjoyed this thread. Lots of good thoughts and interesting takes.
On reflection, it seems that a lot of the 1st edition classes were based on a very narrow take on a character. Not the fighter, who I think was built off of Generic War Game Medieval Warrior from the games roots, but for some the others:
1) Monk- Caine from the Kung-Fu show
2) Clerics- Knight-Templars (which is narrow when you consider all the possibilities out there)
3) Paladins- Lancelot (or at least the limited pool of Pure Knights)
4) Magic-Users- Dying Earth. These guys were not Wizards (ala Gandalf or Merlin), they were characters who had found a scrap of magic and scrounged around the world for more.
5) Thief- Grey Mouser? (I am not so sure that this is as strong).
As the editions advanced, most of the classes became broader to allow for the many many literary types to be built. Which is a very good thing. But for some reason the Ranger seems to cause more conversations than the others.