I recommend reading Engels, the origin of family, private property and the state. If anything I would say that the nuclear family in its current form is more superstrucutural, created by the existence of property relations and propagation of ownership as the only real value in procreation. It was also driven by the high baseline misogyny - as wage labor rose in prominence for men, it also both devalued and suborned the wives into domestic servitude for the husbands wage.

This has created an environment that is incredibly prone to abuse and should not be encouraged, but you can't change it from the top down, it has to come from a change in material relations.