Because the offspring get their citizenship due to the citizenship of their parents. Being born on a military base in a foreign country has no bering on that because U.S. military bases are not U.S. territory.
Yes Doodle. With regard to citizenship, the earth under you when you are popped out is ALMOST meaningless. Simple citizenship is gained by parentage, not acreage. However, natural born citizenship is a special citizenship in which all the stars must be in alignment. Your parents must be citizens, and your butt must fall on American soil. Why this is so hard for supposed smart people to grasp is a mystery to me.