I'm trying to grok how the setting drives play without everything being a hook, from the way the leaves change in the fall at the emperor's palace, to the beer served in the tavern. When I think about bringing the setting into focus, that's what I think of. If each element presented to the players must propel play, then the density of hooks becomes so high that you end up with option paralysis. If only certain elements are meant to propel play, then you are stuck with either the GM telling the players what is actually important, or forcing the players to interrogate every detail to figure what matters.
I am guessing that I don't entirely understand what you mean, though. Could you explain it indore direct terms, or with an example?
I think it is reductionist way to see setting focused play (not saying you are being reductionist but saying the idea that the GM is the only driver via the setting). I think we have also had enough of these discussions that we probably know where everyone stands on them. But what I will say is the GM isn't really driving play in this kind of campaign, the players are. That is the whole point. The setting is important but player goals, motives, actions, etc are the real things that drive play in different directions.