Go Monte--I love it and couldn't agree more.
I once heard a fellow teacher say that "A teacher should never do something [in a class] that a student could do just as well or better;" in the RPG context, I would say "A rules set should never do something that the humans can do just as well or better." This goes for the GM and players alike.
In D&D there is really only one core rule: you roll a d20, add some kind of number, and compare it to a target number. Then you have a group of what I will call primary elements, which include hit points, levels, ability scores, classes, races, etc; then you have what I will call secondary elements, which include powers, spells, skills, and all the stuff that a character can do. We could further differentiate a tertiary category, which includes stuff like conditions and all of the many possible modifiers that can be applied.
The big flaw in WotC D&D (3E and later) is that it mushed all of this together into a core rule set, with very little differentiation. In early D&D, you pretty much had only the primary elements and then everything else was DM adjudication and player imagination; AD&D complexified this with more secondary elements and a smattering of tertiary elements; 3E brought in a deluge of tertiary elements, which are now strongly codified in the 4E battlemat experience.
This has also furthered the notion of the DM as "machine operator" or arbiter, and in a sense the opponent to the players. This, in my opinion, is directly related to the unacknowledge massive elephant in the room that, whenever it is brought up, causes quite a fuss: the influence of video games on tabletop RPGs. In a video game, the players is fighting "against" the machine; the GM, such as it is, is the program itself. For a generation brought up on video games, the GM is the enemy--the operator of the machine or program that you, as the player, are trying to win. This, I believe, has influenced the basic assumptions that later generations of role-players--those that have been playing for 15-20 years or less, even more so those that have been playing for 10 years or less--have about the role of the GM, and the relationship between the players and the GM (and, really, the individual and the world, but I'll leave that for now).
Now we could say that anyone can do whatever they want with any game. But the thing is, the rules form and guide the game experience. WotC D&D, but especially 4E (which I enjoy, btw), is designed in such a way that there are so many secondary and tertiary elements that the player is further removed from their character, and ends up running their character like a piece on a board game or a video game avatar (at least in combat, which is why some have noted that 4E is like two games in one: the actual role-playing game that takes place outside of combat, and combat that is essentially a miniature skirmish game).
If I had my druthers, 5E would be designed around only the primary elements I mentioned above as core, with secondary and more so tertiary elements being optional, even within a specific context. That is, if a group or the DM wants to consult the rules-as-guidelines in a given situation, go for it; but this approach shouldn't be hardwired into the basic game, but rather optional. Even better, if the designers did their job well, 5E would be able to easily create an "Old School" experience or a 4E battlemat experience, depending upon which secondary and tertiary elements were used (or, to put it in Mearls' terms, how far up the complexity dial was turned).
The only way that D&D is not only going to thrive but survive, imo, is if the priorities are re-envisioned whereby the game system, as well as the technology (DDI, apps, etc), serve that which is unique to the tabletop RPG experience: the play of imagination, the world being within consciousness, not on a computer screen or game board. I'm all for new technology and evolving rules, but they shouldn't be about bringing the game closer and closer to a video game experience; so far that has been the direction, especially from 2E to 3E to 4E. The articles by Mearls & Cook give me hope that 5E may be a change in that trajectory.