During my brief career at New York Telephone in 1967, I worked with an installer who had many years of service. He was always being asked to work overtime but would inquire if call director work was involved. If it was,he refused. He explained that between pulling 75 (or 150)pair cable through underfloor ducts,and terminating thousands of pairs, it wasn’t
worth the headache. This was lower Manhattan, some jobs could be for over a hundred sets.