[The GM's] job it is to keep track of the backstory, frame scenes according to dramatic needs (that is, go where the action is) and provoke thematic moments . . . by introducing complications. . . .
This is still where I disagree. Or at least rubs me wrong.
I don't frame based on dramatic needs. The drama occurs in the course of the story the players write in the world I present. I see myself as an impartial referee in that regard.
I realize that I'm the one who populates the world, develops the schemes and plots, decides what the NPCs and monsters do, etc. But when I frame scenes, it's not really for dramatic effect. Here's the facts, do with it what you will. I think of it like walking outside your door, or walking down a busy city street. There's the physical description of the city street itself, then there are people, engaged in various activities and such. Some are friendly and say, "hi," while others keep their eyes down to avoid conversation. There might be something exciting happen - a tavern fight, or somebody chasing somebody, perhaps a thief that stole somebody's purse. Sometimes something more direct and confrontational happens, like a group of thugs wanting to remove the PCs of their valuables.
While that sort of encounter may provide a dramatic scene, it's really up to the players/PCs to do something with it. Just like if you were on the streets of NY and a group of thugs came up and confronted you. I have no specific concern for the dramatic needs, that's not inherently my job.
Sure, I also provide story arcs for the NPCs, monsters, and such, and the players intersect with those - but until the PCs do something, until they latch onto something and run with it, there really isn't any drama. And yes, that approach is perfectly valid way to handle things, but it's not the way I do. Essentially, my approach is an extension of the classic dungeon crawl. Open the door, see what's behind it.
I do provide plot hooks, including as many as I can that connect to backstories and such. But they are still just things. I'm not writing the drama, just the facts. The players provide the drama. In my campaign, the ranger was sold into slavery by his brother, after killing their father. So sure, I provided some dramatic framing. But from there, it's all a question of what they do. They did spend time looking for clues, etc, hunting down his brother. So I got the ball rolling at the beginning. But it only had some dramatic purpose because they players decided that it was worth following.
I also don't consider it my job to "introduce complications." I get that games like BW/DW specifically work that into the rules. That's one of the reasons I don't like them. While I agree that a failed skill check can include more than just success or failure, and they can include some incidental complications or consequences, I don't like the systems that focus on the DM generating a new complication that goes beyond that.
In an earlier thread, there was a discussion about what could be included in a climb check. One of the examples was the Mission Impossible scene, hanging from a rope to disarm a trap without touching the floor. This was a LARP example, and what actually happened in real life is the guy's gun fell out of its holster, he almost caught it, but then dropped it, and it set off the trap.
I think that's a perfectly reasonable consequence of a climbing failure in that particular situation. While there are other possible consequences, the fact that they are hanging upside down specifically creates a scenario that wouldn't occur unless they were in a situation like this - the gun falling out of the holster since they are upside down. If they hadn't thought to secure the gun, then a failed check could include the gun falling. Like in real life, there's a chance to catch it (a Dexterity check or save), otherwise further consequences occur. While this could be considered a "complication" I see it as less, simply a consequence dictated by the laws of gravity and a failure to consider it.
On the other hand, when the DM is instructed to introduce a complication, I've seen all sorts of far reaching complications. For example, on the failed climb check, the DM introduces somebody starting to unlock the door to the room because they forgot something. But it doesn't seem to have a direct correlation to the failed climbing check. Or if there are guards outside, the failed climb check causes the character to sneeze.
Part of the reason is that in the framing/complication model, the check is usually not for a skill, but directed toward the goal. The goal here not being caught. So failure means that anything is possible that might prevent that goal from succeeding. For whatever reason, that approach rubs me the wrong way. Perhaps it has to do with the GM having too much freedom to alter the course of the story, where I prefer that the majority of the story to be driven by the PCs themselves.
The Star Wars example, Luke's family being killed, is pretty dramatic. I probably wouldn't ever spring a consequence like that without some pre-planning. In other words, it wouldn't be created on the fly to introduce a complication. The story arc itself is OK. The stormtroopers are following the droids, and killing witnesses. There really isn't any possibility of figuring that out, or any warning. So if Luke purchases those droids, then the direction is set, it's a question as to who is home when it happens. These types of scenes, a strongly dramatic scene from me, are usually the start of a campaign. Something that is so defining that it has a long-lasting impact on the direction of the rest of the campaign. But after that, events like that occur are almost entirely player/character driven.
So I consider my job to simply frame the scene - not the drama, just the scene. And I'm not their to introduce complications, but to adjudicate the results of actions. The main reason I look at it this way is because I don't consider it my story to write. Because I have an entire world full of people and monsters to write about. Which is fun for me, but probably boring for everybody else. So the game is their opportunity to write the story, and bring that word alive.