"the one-view-per-title, per-person rule has not changed. This was something the unions insisted on when the archive was founded."
I don't think this was the case from the very beginning. I seem to remember a regional production of a musical getting busted for copying the staging of a Broadway show. Upon investigation, it was found that the director of the regional production has gone to the archive and viewed the show multiple times. I thing it was then (and I don't remember the year or the show) that the one-view-per-title, per-person rule came about.