[cthalupa]

I think the discussion itself is kind of a weird one to have. Most of the author's point is about OD&D, but OD&D itself was a very short lived phenomenon. People pretty rapidly moved to either the AD&D or B/X line of products, and there are some departures in the rules, and both lines added official rulebooks that do explicitly contain things that go against a lot of the author's points. And basically every table from the start has had a pile of house rules (or at least generalized processes) to handle situations not explicitly called out in the rulebooks. Much of the question of feudalism is more of a campaign setting question than a rules question - plenty of people played campaigns back in the day in settings where there was royalty, where you would have to purchase or otherwise acquire land rather than just plopping down your claim somewhere.

The argument the author is making is messy because it mashes together the dichotomy of old school D&D versions vs. the modern equivalents. Originally, D&D was a framework that you built on top of. You might adhere fairly closely to the rules as written, but they were intentionally quite basic in nature, and additional structure and systems almost always came as part of your campaign milieu and table-specific needs. Modern D&D has significantly more rules - it's a more complete game, with all the good and bad that entails. Neither have a mechanism to force you to use any specific portion of them, and many people don't.

I agree with the sentiment that D&D is not pro-medieval, though depending on which rulebooks you use it might incorporate aspects of medieval society and structure. I also don't think it's anti-medieval, because that implies structure that isn't there. Any given campaign or table might be more or less medieval than any other and still be totally authentic D&D.