Some people put others down to feel better about themselves even when no personal attack was made previously, so this could be a reason this is done. It also seems that there are some people who cannot understand that not everyone wants a child or all that comes with it. Perhaps those with children want others to share in their misery? I know a small number of men and women that will honestly say if they had it to do all over again they would not have had children as much as they love them. Some of the reasons they cite include cost, body changes that are permanent some of which are threats to their health such as diabetes, lack of personal or free time, increased stress, etc.