I agree that statistical correlations of marriage with various outcomes are very weak evidence of a causal effect. However, I hope that people will apply this

I agree that statistical correlations of marriage with various outcomes are very weak evidence of a causal effect. However, I hope that people will apply this logic to ideas that come from both the left and right, e.g. the NYC ad campaign against teen pregnancy. The same applies to the general principal that the government should not promote particular lifestyle. If girls want to get pregnant at 18, how is that any more the government's business than if they want to not get married?