There was a lot of beauty in the pairs contest back then, ot should come back.
European federations still run some pairs contests. Even the IFBB has it in its world amateur and here in south america, although with fewer couples than during it´s prime in the 80s. However, it is starting to regain some status, as it seems more competitions are starting to have this class, and slowly more entrants to the competition.
As Alison said, maybe it vanished because girls were getting as big as the guys. But since there are a lot of classes and non bodybuilder-looking kind of girls, maybe that´s a reason for its return. Hope it keeps increasing