I've run a number of Pathfinder adventures, and I have to agree that I will often run across background information in the text (or even non-background stuff) that makes it more difficult for me to run the adventure as written. All of this fantastic story material is provided that is practically impossible for the players to discover during the course of normal play. This can lead to really odd, confusing moments such as that in Burnt Offerings where the PCs stand an almost inevitable chance of witnessing a sack of pickles fly out of a goblin tower. In actuality, the pickles were tossed out by a pair of goblin pickle thieves who assume they've been caught when they hear the alarm raised, but there's absolutely no way for the PCs to actually discover this (the only clue being that one of the pickle barrels has a hole in it). Sure, this is solid, amusing stuff to read if you're just browsing through the modules, but it certainly lends them a feeling of the adventure having been written to be read, rather than to be played. I have to imagine that a pretty significant chunk of Paizo's subscriber base is people who stand practically no chance of actually getting a group together and running a game, but like to imagine what it would be like to do just that while reading through the adventures.
