This means that for me RPG books might as well be written in any order. In fact I wonder whether I wouldn't be better suited with an RPG book that would come in a folder and you could just pull out clearly defined sections to read - a completely modular setup.
This also means that RPG books (in which the writing is complete shit as a general rule anyway) need to be really interesting at every turn if they're to be really successful. Each page has to have something good on it - preferably something which gives the reader ideas, in a presentable and quickly accessible way. The reader isn't engrossed in War and Peace. He's grabbing a book off the shelf and flicking through it, or sitting on the loo, or he's a player in a game idly perusing while his character is otherwise off-scene. The best book is one that works with that in mind.
This is part of the reason why I quite like how Yoon-Suin turned out. I can't claim it being deliberate. But I think one of its successes is that when you open it up at a random page there is generally something on there that you can get interested in. It isn't just a page of blah, which is what you tend to get with most RPG books.