Why didn't Zhu Yuanzhang give this position to Judy?

In February 1368, Emperor Wu of the Han Dynasty began to create a tradition for this dynasty, that is, to make Zhu Yunwen's father Zhu Biao the prince, because Zhu Biao may actually be the son of his first wife Ma Huanghou in name. Emperor Hong's goal is to establish a formal principle for the legal succession of the throne, hoping to put an end to future disputes about the succession of the throne. Zhu Biao is not like his father in many ways: he is a gentle and educated man, but not very brave. Although Ming Taizu was impressed by the military ability of his fourth son Judy, he still thought that Zhu Biao was his suitable successor for the benefit of the dynasty.

Under the patriarchal clan system, it is important to establish a prince before establishing a saint.

Prince Zhu Biao is the eldest son, and Zhu Yunwen is the eldest son, so from the patriarchal clan system, he is the first heir. The so-called official position is that the wife is born, and in the royal family, it is the queen's birth.

Judy is an unmarried woman, so when his eldest son and grandson exist, he has no right to inherit. After Judy succeeded in usurping the throne, he boasted that he was born in Ma Huanghou, but the result was actually a deceptive trick. The academic community has reached a conclusion on this issue.