With the amount of influence and reach D&D has... I find it hard to believe this won't take on a life of it's own and become THE way these styles are defined by the vast majority of players. It's one of the main reasons I'm not sold on the DMG being prescriptive at all, because regardless of how many disclaimers they put in the book whatever they define is going to be taken by most as truth.
If they're offering more than one way to do things, and say things like "there's more than one way to do things, and every game is different, try different methods until you find what works for you and your players" then I don't see a problem. Those who've been playing long are, I expect, well aware that the rules can be changed to suit.
Maybe an analogy would help... currently, the DMG (and the 5E rules largely) are like a fill in the blank question. I'd prefer to see a multiple-choice question, with e) come up with your own thing as an option.
We already have plenty of options where a single sentence here or there has lead to years of "this is how thou shalt play" arguments from some people. We don't need more.
And yet in one of these threads, you said that even in early editions you played where it was a focal point of play, your group happily abandoned any kind of encumbrance/carrying capacity and resource management type rules because they didn't suit.
But how did you know to do that if the book was saying that these are the rules?
How did anyone play a campaign without keeping strict time records?