When the crown was routinely going through people's correspondence, or barging into homes and seeing what was there, how could one not understand the Founding Fathers wanted the people to both be secure in their homes and possessions as well as have the right to privacy in their lives?
It's like people forgot about how in the weeks prior to the battle of Lexington and Concord, the Red Coats were stopping everyone traveling, detaining them without cause and searching all of their possessions, luggage, papers in the hopes of finding documents pertaining to the rebellion or weapons / supplies that could be used to support them.
THAT is why we have a fourth amendment. And it is DIRECTLY related to privacy. And anyone claims to be an "originalist" and denies this, isn't an originalist.
Also, this finger pointing to these phony "originalist" as being authentic pro-constitutional people is a gross straw-man argument.