Using your form, Narrativism is "Here is an audience and a premise, create a story." Gamism is like "here is an audience and a game, win it." The audience (the other players around the table) part is important.
Simulationism is "here is a world or a genre, live in it". GNS considers genre emulation to be simulationism. It says sticking close to a checklist of genre tropes is more akin to simulating physical or historical reality than story creation. Some people have problems with this but I am on board with this, at least theoretically.
Anyway my point about 4e is, while I know at least pemerton finds 4e's scene focus and skill challenge mechanics useful for narrativist play, I find it misleading and frankly kind of pretentious when people try to argue that something like Come and Get It is useful for narrativist play. The idea between CAGI and related dissociated mechanics is the 4e designers chose to "brute force" class balance by homogenizing (and nerfing) the player-directed mechanics. It's about balance, which is generally a gamist technique.
There is no necessary connection between a dissociated mechanic and narrativism. Dissociated mechanics can support gamism, narrativism or simulationism, or they can be pointless and not support any creative agenda.
I certainly don't think dissociated mechanics are necessarily bad. I think they should be used more carefully than they are in 4th edition.
You managed to rephrase what I said into something longer and somewhat less accurate, but which uses more irritating words. That'd be exactly what's wrong with those terrible essays, yes (a world already IMPLIES a genre man, you don't need to separate the two, and gamists enjoy playing games more than they enjoy winning them (a hard fought game that is quality and lost is more fun than an easy game and an easy victory).
As for Come and Get it, no. It's no more based in narrativism than "Improved Trip" is simulationist. D&D has always had strong gamist elements. I mean 1E is almost pure gamism in many respects. It's a fun ability that is fun to use and fun to narrate - and also the whipping boy for far too many things. If you can't handle a fighter luring a group of enemies in close and then punishing them for their mistake, you probably have an issue with a TON of genre fiction. Because warriors luring a bunch of people in and then going nuts is pretty much a staple (watch goddamn Buffy the Vampire slayer and you'll see Buffy Summers do exactly that many times - ye gods this is not hard to find examples of). So it's a fun gameplay element that also mimics a lot of fiction and was drawn from it (look at the name itself and you can see that).
And that's where your entire argument, to me, runs off the rails. Come and Get it is fun to narrate! It's fun to use from a gamist perspective. The simulationist is left out in the cold, I suppose, but oh well, can't please anyone.
Now look at trip mechanics. From a narrative perspective, they are the most boring things in the universe - exactly how the trip mechanic works is defined heavily by the rules manual (compare to the very loose ways that 4E gives for being 'knocked prone' which are much more open to interesting narratives). From a gamist perspective, well, they're powerful. And hellishly boring. Trip someone, pin them down, make lots of attacks. Fail your trip attempts - or find something that's hard to trip - Oozes can be tripped (and in fact get no modifiers to preventing it, so pretty easily), so not as much as you'd think - and go back to full BAB spam. It's a game where you have two cards and you always know which one you'll play. And from a simulationist perspective?
Oozes can be tripped. So your simulation fails dramatically.
But somehow the issue of how fun mechanics are at the tabletop gets lost in all this back and forth. Here's the issue - Buffy jumping up on a tabletop, whistling to get the attention of a room full of vampires, and going "hey boys, I'm up here" is good old fashioned fun. Sir Tripsalot tripping the zombie, followed by Sir Tripsalot tripping the Ooze followed by Sir Tripsalot tripping the dragon is good old fashioned BORING. Maybe if your "beautiful example" of non-dissociative mechanics didn't make me want to fall asleep during gaming sessions I'd be a tad less skeptical about your creative direction.
P.S. Can you please find another power other than Come and Get It? Because it's one power in the entire book. I mean why do we even need to defend it? You can't defend the 3.5E drowning rules, they perfectly, in completely clear plaintext, allow drowning to heal somebody. Every system on the PLANET will have a few things that make zero sense (and at least Come and Get It is a fun sort of zero sense in a lot of situations). Go find a few more examples, plox.