>>Over-rigidity can kill what would otherwise be a good love-based exhortation.<<
Being child-free can be from a lot of situations, such as getting married late in life
Or other misfortune that has introduced delays in being reasonably marriageable (as opposed to a baby daddy or a welfare queen). Nobody is saying to be stupid here. But if love can not drive the whole thing, might as well hand the keys over to the devil and tell him he’s won, all hail hate. (However, yes it can. But it needs people willing to believe it even in the face of difficulties.)