You make a valid point that not all straight married couples raise a family and they are not really expected to. However, gay couples cannot create a child (naturally). Hence, they should have no need for that tax cut, correct? Nor does straight couples that do not raise children, but if they chose to, they might need that tax cut. Now, I leave you with this question, if gay's want to get married in order to be considered "married," would they still feel obligated if there was no tax cut?