I disagree, but fundamentally it doesn't matter. What Dungeon & Dragons was designed to be is an entirely different discussion. What's important is you don't care whether D&D is an accurate simulation of the human experience, and don't really intend it to be one.I don't believe Dungeons & Dragons was designed with accurate simulation of the human experience in mind.
And my response to that then is, "Then for a game like that you don't need any sort of game world that accurately models wages, economy, or anything else."
You are the one in charge of what your game is about, and no one - not even the game's creator - could tell you that you were wrong for having a game about that. An RPG system is in many ways like a language. It has some structure, and it may be particularly expressive or inexpressive regarding certain ideas, but ultimately you are the one that gets to decide what to say in and how you want to say it.