Overloading of the word "free" here. Contextually you might be meaning anonymous, unannounced, no justification required. Only anonimity would be harmed by requiring ID and in the case of at risk manuscripts, one of a kind, holograph works of significant value, I could see reasons to say "we have a booking system"

are you being reductionist on this, and "demanding" that unconstrained access exist as a norm?

I don't find identified purposeful access objectionable. I am concerned at the amount of degredation to works from constant public access to them: its a thing in european museums, cultural exhibits, lasceaux..