Basically, American immigration system is based on family reunification and the needs of employers. Needs of the employers cannot be fulfilled without employee family which is again Children.
On a broader view employment category is developed based on the employer’s requirements in different skills that are valuable to the U.S. economy. Immigration system view is different than us who are in different category lines. They don't care who got in which employment category, as the main objective is the diversity and economy.
I know so many people who does not even know GC process got GC long back. I was also under the same impression that it will come one day. Decade waiting makes me slowly getting into the things around GC and understanding people jumping lines to see the Heaven

. people catch anything when drowning, that may be others leg. Cant blame it.