There are other levels of meaning and other perspectives, so we could analyze D&D in entirely different ways that don't agree with either JB or Mearls/Cook. And we could use various non-game-related schemes as a point of comparison. For example, the Drama Triangle specifies three dramatic roles (Victim, Persecutor, Rescuer,) which we could actually almost line up with JB's thematic pillars, with some tweaking: characters start vulnerable (Victim,) are challenged by the arrival of a threat (Persecutor,) and with luck and skill reverse the roles, rescuing themselves, at which point the characters face some new challenge, beginning a new cycle.
Of course, if we analyze it that way, we're not so much talking about either the higher, thematic level or the lower, mechanical level, but the middle, functional level. Here's a different structural level analysis:
- Character (role concept)
- Adventure (setting concept)
- Resolution (interaction of role and setting)
- Expansion (elaboration of character and setting)
Character starts with the assumption that the player interacts with a fictional world via a role (fictional person;) character creation is a way of distinguishing characters. Players describe their characters, and someone (traditionally, a GM) describes a situation (adventure) as a response (what the fictional world is doing around the character.) This back-and-forth interaction between Character and Adventure requires a resolution system or at the very least an agreement as to how to decide which side wins when the two clash. As the two elements interact, characters can advance in level, gain new abilities, acquire wealth and possessions, or explore wider areas, while the setting expands in its own way as the GM (or whoever's responsible for setting up adventures) adds more details to the fictional world.
So, there you have Four Pillars of D&D. They're no better than any other set of pillars, but they illuminate a certain way of looking at the way D&D works.