They didn't make any sort of "decision." To assert that they did would imply that they had weighed the facts of something. They simply floated along with the rest of the Country in Ignorance of a discontinuity.
That there can be no other alternative? Are you even willing to entertain the notion that they in fact do understand the NBC very well and simply came to a different conclusion then you?
No, because such a notion requires the rejection of all the historical evidence which has been accumulated on this issue. Occam's razor dictates that the far simpler explanation is the more probable.
That they could so blatantly ignore relevant documents and precedent can only be explained by a lack of knowledge regarding them. I am giving them the benefit of the doubt by assuming they are unaware of the historical support for the Two Parent requirement.
Again I point out. Indians were "born" here, but were not even CITIZENS, let alone "natural born citizen" until 1924. Slaves were "born here" but they also were NOT CITIZENS until 1868.
You can twist it any way you want, but these two GLARING EXCEPTIONS demonstrate that being "born here" is NOT the defining characteristic of a Natural born citizen, or the Slaves and Indians would have been "natural born citizens" from the very beginning.