I think it has to do with not having as widespread a reputation as some of the higher ranked schools. Fordham places mostly in NYC, where as the rest of the 15-30 might place in more than one major city. For instance, a bunch of the mid-western state schools may place in say, Chicago AND Minneapolis, or BU in Boston AND NYC. Therefore, it's name is less well known outside of the city, and would have a lower repuation score.