The Supreme Court has ruled otherwise: https://en.wikipedia.org/wiki/United_States_v._Wong_Kim_Ark
The courts do not make law.
An important line from the 14th Amendment: "and, subject to the jurisdiction thereof."
Jurisdiction has nothing to do with geography. It refers to political allegiance to the United States of America.
Article 1, Section 8, Clause 4: Congress shall have power to establish a uniform rule of naturalization.
The Constitution clearly gives Congress that power, and they have used in in the past:
The 14th Amendment excluded American Indians as U.S. Citizens, because they felt that they had an allegiance to their own national tribes. Later, Congress reversed course and legislated, under the 14th Amendment and under Article 1, granting US citizenship to all "Native Americans".
They have that power, and a simple clarifying bill would specifically state the language, and codify an end to the practice of "anchor babies". That's why the President correctly threw the DACA issue back into Congress' face.