Because it either places the onus of proof of innocence on the occused, something that is unconstitutional in the U.S., or removes fair use. There is no stipulation that the process of makign an archival copy need be done by myself, only that I am legally allowed to make AND to possess an archival copy. These are seperate rights, the right to make archival copes, and the right to possess such copies.
Makign an act illegal is in fact a direct invitation for said witchhunt. Why make something illegal if you have no intention of prosecuting offenders?