I think it makes for more responsible GMing, in terms of introducing fictional elements.
When I run Lacuna or Apocalypse World, I am specifically and immediately responsible for everything I narrate, as I am narrating it.
In Burning Wheel, I create an NPC beforehand with stats. When the PCs go up against him, the capabilities of all characters are set, and dice and player choice determine how things shake out. But if that NPC sneaks up on the PCs and murders one of them, we roll dice for it, and what happens happens.
In Apocalypse World, before I introduce something or make a move, I have to ask myself if it works in the fiction. Like, I can totally kill a PC for a flubbed roll, or a bad decision. But is that what would happen?
In BW (to use one example), I can be true to the stats and the predetermined capabilities of my NPCs, and when the PCs come into conflict with them, we see how it shakes out. I can go into a conflict with an over-arching goal, and play through it, and see the results at the end.
In AW, I have to be true to the fiction, and refer back to it, every single moment. If you jump out in front of Jimenez and unload your assault rifle at him, and roll snake eyes, what happens? I can't say "he rolled better than you, you lose 3 from your disposition" and then describe how he does that. I could say any of the following:
* Your gun jams. Jimenez just laughs at you, and you are paralyzed with fear.
* Your gun jams. Jimenez cuts your face in half with his machete. Take 3-harm.
* You empty the clip but the recoil sends every bullet high. Jimenez tackles you to the ground.
* You empty the clip... into Joe's Girl, who's standing next to Jimenez (player: "oh shit!")
* You're about to open fire when a mortar round hits the building next to you and explodes all over (player: "...wait, what?")
So which one do I say? I have to evaluate, in that moment,
a) which one is the kind of thing that happens in the world I'm describing,
b) how would my characters react, according to my conception of them,
c) AND what will happen because of what I say.
This last one is important, because I could just say "Jimenez cuts your head off, take 11-harm (ap)," right? I mean, if my BW villain does grey shade damage and he hits the PC, guy's dead. He knew the risks. But when I decide what move to make because of a flubbed go aggro roll, I have to be responsible for results of what I say.
Added on to that, and most importantly: I can say all those things I wrote above without waiting for a roll. It's not the failed roll that lets me say them, it's my role as MC.
In BW, you have to be very mindful when you set up a conflict. Once you set it up, it goes, like a machine (and if you set it up wrong, it sucks). In AW (and Lacuna), you have to be mindful of everything you say, as you say it, but not as much as when you set up that BW conflict, because the situation can change moment-to-moment.
BW will teach you how to set up good conflicts, or keep your skills honed. AW and Lacuna (and like Ghost/Echo, too) will teach you to umm I ran out of words keep what you say consistent with the fiction you're building, to your own conception of the fictional world and the story/narrative. Something like that okay bye.