Wow Matthew. As John says, you really have tried!
I think the -1/-2 foe like this mechanical badarssery lever may cater to these player's sense of 'fair', but on the whole what's then to stop them querying all such narrative 'dick' moves and asking for such modifiers to most rolls just so they can 'make a move'? At any rate, I hope that it quells some of the dis-satisfaction of your gamist die-hards :)
I mean, most of us avid story gamers love the choice embedded into the 7-9 result, and in my little group's experience, as they level, they consciously choose moves that give them narrative options as move results in preference to mechanical ones, because if you are savvy, they give you so much more authorial power. Higher levels usually equate to greater narrative strength, they love this!
As an actual example; our 2.0 ruleset, ancient Dragon that lived under the ruined complex deep within Phoenix Mountain was spawned through my own vague desires for a Smaug-like danger and subsequently fleshed out through provocative questioning and numerous spout lore and discern reality rolls (most of which were failures or 7-9 results).
They authored themselves that it was folly to even attempt to encounter this beast without hefty magical wards, a razor edged wit, good knowledge of the dragon's escape routes from her lair, a means to protect oneself against dragonfire and scrupulous ethics. The one thing I introduced as GM was that non-magical weapons would leave no lasting wound other than the memory of the one who dealt the blow. The wyrm then fabled to seek her antagonist's lot for retribution.
What's to stop a lvl 1 fighter from garnering a magic weapon and seeking out the beast with the potential of slaying the mythical creature with one lucky hack and slash move? Only getting into the narrative position to do so.
My point I guess is that in my experience, to 'win' this sort of player over is to not give them the mechanical crutches they desperately find comfort in, but enlighten them with the fictional power of moves. Disclaim decision making to them more often, especially when its not 'their' move, re-incorporate their authored NPCs, locations and artefacts as often as you can, making them integral to the emerging story. Allow them to develop a quest mythos for defeating legendary beasties and the then step-by-step fulfil them, gaining levels along the way and ultimately slaying the creature in a very satisfying narrative arc and effecting the fictional details of the world in ways a -1/-2 never could.