hawkeyefan
Legend
You've used this example many a time but I still don't see how the system can allow one very obvious, realistic, and fairly-common-in-real-life outcome to occur: that the spellbooks are there in the tower but Thurgon simply missed them in his search.
If you set aside your preference and expectation on how this works... that the books are in a specific location predetermined by the GM... the roll to see if the books are found in Evard's tower determines only if they're found in Evard's tower.
The GM doesn't actually need to know where the spellbooks are.
I say this because the way the system seems to be set up, if Thurgon looks for them elsewhere and succeeds in his search that places those spellbooks at that location and not in the tower; and if he keeps looking in different places he's bound to succeed on a roll sooner or later and find them.
What's the problem here? My familiarity with Burning Wheel is almost nil, but I expect that there's some risk or cost involved with the roll, or at the very least some other limitation, even if it's only based on what may be reasonable (such as spellbooks being present in a wizard's tower), that keeps the player from searching for the books in every single scene. They wouldn't declare they're searching for the spellbooks in a random roadside inn.
Games that allow for this kind of thing have clear processes and principles involved that help prevent the kind of absurdities that you're envisioning.
To me, it seems fairly accurate. They seem upset at the idea that their character would have to have the world described to them, rather than automatically know what it's like (and by that, it means "make it up themselves).
I think a better way to look at it is more about the interaction of two things: what a character is likely to know and the ability for a player to have input into the game.
I don't think that anyone would expect to already be familiar with some lost tomb that's only recently been found and which they've entered for the first time. When a character encounters something new or something unknown, of course the GM will need to explain and describe it.
But when it comes to things a character could conceivably know, or that they outright would know? Why shouldn't the player have a say about that? This then allows them to have some input on the game, and it's all still through the lens of their character.
It's not about quantum spell books or authoring things beyond the scope of the character.