Excellent thread and excellent points being made!
Just to clarify my own position since I was part of the original conversation that spawned this.
My basic point was that in much of fantasy (both as a genre and an RPG) we tend to gloss over (the term I used was lampshade) the icky parts of what I mistakenly referred to as feudal periods. Again, people got a bit more caught up in chewing up the exact definitions rather than the point I was trying to make.
The point is this - yes, we use a Ren-Faire approach to a fantasy setting that is very loosely based on pre-industrial cultures, typically from Europe, although certainly not exclusively that. But, we then completely romanticize the whole thing. We have "good kings" that do good things and are "good kingdoms".
Meanwhile, players will absolutely lose their minds over things like the Wall of the Faithless in Forgotten Realms. Or the Cataclysm in Dragonlance. But, have no problems with autocratic governments where your character really has no rights or freedoms. But, because we ignore all that (mostly in service to creating an "old west" approach - itself incredibly ahistorical and romanticized) we wind up with these settings that, if you step back and pull off the lampshade, you realize that these settings are hiding a lot of nastiness that we just gloss over.
The reason for this whole sidebar was a comment about how war-games of the 1970's which formed the basis for a lot of D&D, also lampshade a lot of the more icky parts of history in service to fanstasy.
Again, of course we do. Heck, how many people play Grand Theft Auto and love it? Are they horrible people for liking the game? Of course not.