Without more people society has no future, eventually everyone will die. So you need to make a decision: will my kids be a net negative or a net positive to future society?

In this case with what little I know about seymour333's situation (one HN comment) I would call it a net positive because these kids grew up in an environment where they or their parents experienced upward social mobility. Perhaps mom and dad can't break the middle class ceiling, but since the kids know escaping poverty is a thing that gives them incentive to elevate past middle class.