My biggest issue with the Model T example is that it just doesn't fit. RPGs don't have "technical advancement."
There is advancement though. It's not in the area of technology or efficiency, but in the area of experience and knowledge, and no less important.
When Gary first set out to publish the original pamphlets, how many D&D gamers do you think there were in the entire world? A couple dozen? 30 years of accumulated experience, millions of sessions, thousands of groups the world over writing, talking about, and playing the game... All of that experience and real world testing absolutely informs game design, teaches designers what issues there are, gives shape and form to direct decisions that inform the style of a game system from top to bottom.
I sincerely doubt when making the game originally Gary wrestled over the player skills versus character skills debate (just by way of an example). That is an issue that arose with the thief class introducing skills, NWP being introduced in Dragon and the like. Those advancements came about from the player base growing and playing the game, experience from many sessions informing the issues of the day.
Now, we can identify these issues, designers and fans of theory discuss them at length, new systems are built around answering such questions. Advancement isn't in answering such a question definitively, but in recognizing that the question exists and having knowledge, gained from play experience, of the merits and flaws with the different approaches.
That's why I say this whole new-old thing is just nonsense. Most of the old school community doesn't play the actual older edition, but a retro-clone designed to emulate elements of the playstyle that edition, and that editions players at the time, represented. These retro-clones are designed with the knowledge and experience of the game industry as a whole, informed by the years of advancement as discussed above. The ways in which we gamed back in the day varied pretty much by the group, but a common, shared knowledge arose, issues were discussed and argued and answered in many cases, those answers informing the design of the next edition. That is to say, the designers of the next edition were informed by the community on what was more commonly played or where the players more often fell on one side or the other of a particular issue. The retro-clones are more like alternate reality versions of an edition (or the way the next edition could have gone, instead of the way it did). But for every group that played the game that way there were a 1000 that didn't. The design decisions that informed each new edition weren't born fully formed from Zeus's head, they came from the playing community, as did the designers.
We are all, really, playing the same game, in all its glorious forms.
