Ovinomancer
No flips for you!
I meant to, but it was a long(ish) post. I think the reason you're invoking story has to do with the same things above -- you have to prep an area for the current PCs in case they follow that lead you just dropped. If, later, the reason they're going to this area has changed (or even if it is the same), the prep needs to be adjusted because PC abilities have changed.@Ovinomancer That's probably about right. I think I'm including the idea that revising prep might be about story stuff at least as much as character capability stuff; and I think some of the difference in prep between D&D 5E and BitD is about division of authority (in 5E the DM has authority over the setting unless he specifically shares it--and I mostly don't--whereas it's my understanding the DM in BitD has much less authority over the setting) but that's not so much disagreement as something you just didn't mention, I think.
If you're advancing the story in the area because you think it needs advancing from where it was when you first prepped it but the PCs didn't engage it, well, I think we're back to @Manbearcat's solitare play. And, I don't think this is a bad thing at all -- it's very enjoyable for the GM. I don't think the point is to say that this solitaire play (meaning, for me, that it's just the GM playing) is bad or should be avoided. I think his point, at least the one I'm picking up on, is that it is unnecessary to present a vibrant world, a "living world." It' really entirely for the GM. And, that's fine!