Maxperson
Morkus from Orkus
That logic puzzles me.
You're right that nothing explicitly supports the use of player knowledge, but nothing explicitly denies it either.
That leaves it in the same category as, "Nothing explicitly supports a longsword hit detonating a nuclear explosion, but nothing explicitly denies it either." Absence of denial does not equate to allowance. There are billions of things that the game doesn't explicitly allow or deny. The DM has to actively alter the rules to include the vast majority of things that are not explicitly denied.
It's a lot more support than the absolutely nothing you have supporting the unlimited use of player knowledge. Is it a tremendous amount? No.And even with player knowledge, knowledge skills...even the specific "recall lore" use of them...is plenty useful, because players will often not know something, either because they don't think they know, or because they think they do and they're wrong. So to conclude that the presence of knowledge skills suggests that player knowledge is verboten is just....well, that's just not a valid conclusion. The most you could say is that the presence of knowledge skills is not incompatible with a no-player-knowledge houserule.