Family is a concept, built on genetic reality. If human beings concentrated more on the genetic and less on the sentimental aspects of family, the species would advance greatly.
The sentimental aspects of family are based in primal fear and dependence. Family is the modern remnant of tribe. Tribalism gave way centuries ago in civilized societies to nationalism. The family became a day-to-day functional unit within the nationalist structures. Family was a vehicle for maintaining property, industry and wealth.
Family identity will gradually be superseded by social human identity as humanism and education erode confidence in superstition (religion) and hereditary wealth (oligarchy) as sustaining institutions of democracy and social well being. The advancement of science in the face of staggering environmental degradation will lead to an understanding that family identity is less important for the species to survive than human identity.
Sentimentality is the enemy of science and the enemy of practice. The first liberation of practice is the liberation from sentimentality toward family of origin. This is often called 'growing up'. Practice entails being equally responsible and compassionate to all human beings, including the practitioner's family of origin. This is difficult. Practice often is.