Think of an "updated" version of Monopoly that changed all the properties, utilities and tokens.
Some people will like the new, different version -- case in point, all the College-opoly versions.
But some people enjoy the history and experience of playing Monopoly with the classically defined elements. I would daresay that most people enjoy this, as the (almost) original version of Monopoly is still sold and bought more often than any of the "updated" official or clone versions.
D&D has always been inclusive of new ideas in fantasy (even when those "new" ideas come from people inspired by older editions of D&D!), but I think we are now reaching a breaking point between personal preferences.
Starting with 3.0, the grumbling began about the anime and video game influences on the game. With 4.0, it seems that even more of those elements will become core for the game.
Personally, I don't mind new fantasy. However, I think new fantasy needs its own RPG. I prefer my D&D with classic tone and fluff.