I have made use of dance in my plot, because, well, it has a long tradition of appearing in literature. Dancing allows people to be intimate, almost private, in a public space, it is a good opportunity to converse – used to great effect by Jane Austen for one. All very convenient for moving a plot along.
All societies have dance; it is a universal human activity throughout history. The reasons that we dance may vary (see here for Lindybeige’s video -> interesting theory about why some men don’t like to dance), but some form of dance will always be present. In the absence of television, the internet etc people will need entertainment and society. These human needs have to be met by a real world activity and dancing used to be hugely popular, as a pastime, as way to meet potential partners. Thus I believe that dance in some form would survive the apocalypse and thrive in a more human-centric world.
Jeremiah Hope 