And here you are in agreement with our OP
But that doesn't nullify the idea that the brand is getting even more diluted.
But, that's a bit overstated, isn't it?
No matter the ruleset, you're talking about men and elves and dwarves, with swords and armor and flinging magic around, fighting monsters and earning treasure, right? You're talking about character levels, hit points, six stats, and so on.
I can't agree.
"Ford" is a brand name; it certainly exists and works as a brand name is supposed to. But there are a hundred different "Ford" cars.
I tell non-gamers that I have a D&D game on Wednesdays, even though I play Pathfinder.
I think D&D is more unified then previously, quite frankly. If I say "I'm going to play D&D" to a non-partisan in the Great Edition Wars, they will (rightfully) think "Ok, he's playing 4e" and will have a good idea of what that entails.
And if I say "I'm going to play D&D" to a non-gamer, then they can easily look up D&D and see 4e and, again, have a good idea of what that entrails.
That would be the kids fault for not specifying what he actually wants. It's the same with any other fad present. A brand of skateboard, a type of bicycle, a set of MtG cards, a specific computer accessory, sunglasses, shirts, skirts, shoes, the list of things goes on forever..Child: Mom I want a D&D Player's Handbook for my birthday.
Mom goes to a local comic/game store, run by the usual suspects, and finds a cheap used copy and takes it to the register, and those usual suspects are building some CCG deck and just rings her up and she takes home the wrong thing. 4th edition was wanted but 3rd edition was what was gotten.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.