See the Jay letter to General Washington...
The overwhelming concern shown in the Constutional debates was that foreign influence of the new federal government would be by the traditional corrupt means.
The "natural born" citizenship of the President apparently needed no debate.
The author of this piece is basing his argument on the lack of passage of the "Equal Rights Amendment" by using the male- deliniated definitions used by the Founders. I got to admit it's a valid argument on it's face.