Kesava Kasmiri's Commentary
In regard to the result of undesirable progeny. The intermixture of castes that follow the family customs and honor the age-old Vedic traditions with those that do not causes a degradation in society and leads the family to a hellish existence. Not only this but the anscestors of such a family also suffer as well because there is no descendant qualified to perform the propitiatory rites prescribed in Vedic scriptures such as sraddha and tarpana. . Being deprived of these oblations due to the absence of qualified progeny as a result of destruction of the family structure the ancestors fall down from heaven and go directly to the hellish planets.