That year
Yeh, but probably also technology, the drive for "efficiency", depersonalising and PC. ATC Centres on the other side of the airport, away from the movements of crews and passengers - no visits to the tower or centre by crews with an hour or so between flights. The windows of Sydney AACC C1972 looked out to the TAA/EWA carpark - you could actually see people arriving for their flights. These days you need a ground radar or CCTV to even see the movement of aircraft around terminals. Brisbane tower is not even "on airport" It cost me $18 in a taxi to go the CASA's offices "on airport" just before Christmas.
Sorry, I digress, get back to talking about aeroplanes.
Cheers