D&D does not make one change. I posted on this already, the game does not force anyone to change. The poeple are more important and all that. You even agreed claiming "I don't know any TRPGs that have a rules gestapo".
Perhaps I was unclear or misleading. Perhaps you're getting too entangled in semantics. D&D doesn't force anyone to change. However, the game does change. Because there are no rules gestapo, no one MAKES you change. Just like no one MAKES any other system limited. It's up to the players. However, having accepted the fact that any player can make any game flexible, we're left looking at how the
game itself, by the books printed, in a world where the flexibility of players is a constant. If the creativity of players is a constant, the only variable is the rules of the game. The rules of D&D are inflexible in that they mandate a change in style as you advance, in abscence of players forcing it to be otherwise.
The ability of players of a game to do what they want was never, ever in question. It is the ability of the system to do what the players want "out of the box" so to speak. And D&D, out of the box, is not flexible in this regard. It says "change as you advance in level." If you don't want to change, it's up to the players to force something else. However, this isn't about the people who play the system -- it's about the system. Players can, have, and will always do whatever they want. They are a constant. If they want a style they will find a way to get that style and keep that style, but such things are independant of system, and so such things say nothing about D&D. The flexibility of various systems to keep or dismiss a certain feel as the players desire is a variable, and on that variable, D&D/d20 actually is pretty stringent. Pretty inflexible. This doesn't mean that you can't MAKE it do something else. But it's counting 1-20. You can't just count on 5 forever because it's your favorite number. That's not flexibility.
THe flexibility is that one group can play a low level game and enjoy that while another can play a high level game which is going to be completely different and enjoy that. Other systems don't have these types of changes. That is flexibility; havign one ghame that can suppoirt and change over the course of the many levels the PCs can gain.
Other systems do have those types of changes. Only, they provide an environment where such changes do not require a work-around to avoid. Different "point values" for ponit-buy systems for instance, allow you to play as peasants or superheroes and stay that way as long as you want. D&D's inflexibility is in forcing the players to put in extra effort to work around its built-in pattern of changing play style as levels vary. Out of the box, by the book, assuming that inventiveness of players is a constant accross systems and thus makes all systems equal in that regard, you will play both as peasants and as superheroes and as everything in between unless you MAKE it otherwise.
Changing the style miught be the path of least resistance though, perhaps that's why so many people think they have to.
See, this is the kind of thing I'm talking about. You seem to be in another discussion. Anyone can change any system to be anything they want it to be. This "no-duh" moment brought to you courtesey of Captain Obvious!
"The Path of Least Resistance" is exactly what a thread discussing d20's "brokenness" is discussing. Anyone can make house rules to make things work. D&D *requires* you to make those house rules. That makes D&D inflexible -- if I have to invent my own rules, it's not D&D, it's some subtle variation with the same name. A different shade of blue. Ultimately irrelevant, because, well "no-duh."
Without going beyond the rulebook, assuming that player's creativitiy is a constant, using the "path of least resistance," D&D is not very flexible with regards to keeping a certain feel over the course of 20+ levels. If you want to dispute that fact, stop talking about how players can make the game whatever they choose with a little bit of work. That much is obvious and that insight doesn't add much to a discussion about D&D. Just as saying "Well, Cerulean exists!" isn't going to add much to a discussion about Blue.