At least in my mind, a wise man's conceptualized / generalized purpose is to live as happily as possible given his circumstances, with happiness also conceptually / generally understood to mean that individual's personal "calculation" of the mix of pleasures and pains that are open to him.
As we have seen Lucretius refer to several times, Epicurus apparently observed / held that people differ in their makeup as to what makes them happy. Some people are more group-oriented, some more solitary, some hot-tempered, some mild, and huge numbers of other variations. Or as my wife might put it, some are "marriage material" and some are not. In a very general sense I would suspect that that kind of thing is what Epicurus is getting at, plus all the innumerable circumstances of life that can make marriage / children more or less possible to a particular individual. But always in the context of keeping the goal focused on living happily.