Hussar said:
The measure of the success of a game is how much people at the table enjoy it. No other metric is more important than that. I don't care how well it evokes a fantasy story, if the game is not enjoyed by everyone at the table, it is a failure.
So to tease out more of what I did this morning: why do I play D&D instead of, say, A Link to the Past (which, for my milage, is one of the Best Games Ever (tm))? I could go fire up my old SNES right now and have the time of my life scuttling around Hyrule whacking things with a sword. The game works perfectly, the story is there enough to justify it, I don't have to worry about anyone else, and I have no pre-prep work to do. I just flip on my game and I'm there, enjoying myself.
In fact, I've got a D&D game scheduled for this Sunday. Why don't I say I'd rather play A Link to the Past? Surely I won't have any headaches trying to play 4e without a minis board. I won't have to travel the hour to get to where we're gaming. I won't have to put up with some weird friend tension. I won't even have to get dressed in the morning. I could just wake up, play the game for an hour or so, get bored, and do something else. Maybe look for a better job or surf ENWorld and amuse myself in theoretical design debates. All are plenty of enjoyment for me.
So why am I going to D&D?
Because D&D offers me something, in the gameplay, that none of that does: the ability to evoke a story with friends.
So why isn't this important? It is, essentially, the justification of the existence of, if not the entire PNPRPG industry, at LEAST of D&D.
I don't play D&D just to have fun. I'm a 21st century digital boy. I've got a lot of toys (apologies to Bad Religion). I'm lousy with fun. Furthermore, I'm of legal drinking age, and have ready availability of a legal hallucinogen, so I can make staring at the wall and giggling fun. More fun than D&D could ever be in it's wildest, wettest, most scantily clad dreams.
What makes me choose D&D over these other toys is not "fun." It is a particular style of rarely-had fun that I very much enjoy: interactive, spontaneous storytelling.
Wherever D&D fails to deliver me that, it fails to deliver me the brand of fun I am seeking, and so I'll either seek it elsewhere, or just content myself with a decade-plus old videogame and save myself some time and effort.
In sacrificing everything on the altar of "game-first" you forget that the game itself is "story-first." Without Legolas and Conan, there never would have been a D&D.
Again, this is not a fluff vs crunch debate. You are right, you can have perfectly acceptable, even good mechanics that started as flavour. But, typically, if you start from a flavour standpoint, then bolt on mechanics, you are ingnoring how it plays out at the table.
Actually, your argument seems to be fluff-and-crunch at its core because you specifically argue that starting from fluff gives you bad crunch, while starting from crunch gives you good crunch and can fudge the fluff. I'm arguing that crunch and fluff are two things that you need to get right, regardless of which one you start with.
It's not a case of good mechanics vs bad mechanics - it's a case of mechanics inspired by an attempt to emulate some flavour concept, causing the game to be less enjoyable during play.
Any mechanic that causes the game or the play to be less enjoyable is a bad mechanic. It doesn't really matter what the reason behind it is, it's bad. A flavor concept can give you some dynamite rules. Heck, that's basically what a class is -- a flavor concept.
You bring up the Random Strumpet Table. There's a good idea. Mechanically fine - it causes no major malfunctions in the game, flavour wise perfectly acceptable for the idea of D&D, and causes no major problems at the table. I got no beef with that. I think it was a flavour first mechanic - but, that's a quibble, and it doesn't really matter. It causes no malfunctions at the table. It passes.
But, if you look at the mechanics that DO cause malfunctions at the table, I think you will find that they are primarily driven from a flavour first concept. That the creators of the mechanics are trying to bring out some bit of flavour into the game without stopping and considering how that will actually function at the table.
The mechanics that cause problems come from all sorts of places, and 4e is no stranger to any of the "problems" you bring up. A bad mechanic is a bad mechanic, and trying to muddle out the motives of dead and aged gaming designers is pointless when addressing the problem of bad mechanics.
Though I think the fact that two rational people can look at one mechanic and one person think it's "flavor-based" and another think it's "game-based" means that your terms are probably too vague to be useful in the first place.
At the highest level of "Why am I doing this?", the game and the flavor, the fluff and the crunch, become one experience that compliments itself. It helps me tell a story in a way that isn't clunky or difficult.
A lot of people who have rejected 4e do so because the "flavor" they're looking for has failed to be supported, while it could be supported with earlier editions. The ability to ban paladin and the inability to ban healing surges scratches the surface of part of why this is.