Every rule is gating. You say that as if DM-Gating is a bad thing, when it isn't. It's just playing the game. Every rule in the book and every DM ruling is gating. You do it. I do it. Everyone else in the thread does it. Gating is part of game play.
(1) Not every rule is
GM-gating.
(2) There is a very big difference, in the play of a game (including a RPG) between rules, and discretionary gating. To elide that difference is to elide much of what is interesting/significant in game design.
What I said about the RuneQuest was only to point out that it says in the rule YOU brought to the thread, is that you can't use player knowledge if the PC does not know about that knowledge. I also pointed out how the rule was wrong about cooperation being necessary.
I actually just quoted you saying, of the bit about cooperation, that "The players working together just means that they shouldn't be jerks about ideas on what to do."
But now you're (i) saying that it is something else, and (ii) saying that that something else is wrong.
Also, your description of what the book says as "you can't use player knowledge if the PC does not know about that knowledge" is not very precise, and fails to identify the actual point at issue, which is
who gets to decide what a PC knows? The RQ book actually says that "your first duty is to play within the limits of the characters you generate. Even though you are a chemistry major, for instance, your shepherd character cannot (without learning or training) stroll to a game world village and open an alchemy shop." This does not tell us how PC knowledge is established, although it makes it clear that PC background is relevant (eg shepherds typically don't know alchemy). Who gets to interpret and extrapolate from that background - player or GM - is left unstated, although the subsequent discussion of cooperation strongly implies that it is a mutual endeavour.
Your view that the GM has sole and overwhelming authority in this respect, which - as best I can tell - extends to vast swathes of setting information also, (i) as a matter of practice will tend to produce pawn stance play (as I suggested not far upthread in reply to [MENTION=6688277]Sadras[/MENTION]), and (ii) is a very strong form of GM-gating.
I am currently GMing a game (Classic Traveller) in which players are expected to conform their action declarations, in part, to their PCs Intelligence and Education ratings. We have one PC with an INT of 2 (on a 1 to 15 scale, with 7 being typical). That is certainly an important factor in action declaration for that PC, but my table would regard as laughable the idea that it's a matter solely, or even primarily, for GM adjudication.