I think both statements are true - not all knowledge is recorded by academia, and academia is heavily western biased.

What I suspect is that the down-votes are because the first user was using hyperbole to make a positive comment about our ability to archive these documents and their value. The response points out something that is evident - obviously academic papers do not hold all human knowledge - and shifts the conversation into a not so casual topic of western biases. This sudden shift of the conversation from friendly-casual to geopolitical with little motivation can make some users upset.

OR, as the other person suggested, maybe the mention of 'western bias' is enough to trigger some.

the downvotes are due to the bullshit "bias" claim.

let's you know they're a tankie...

Not every human knowledge is written ;)