Responses
Maybe it is a check and balance thing, he may not want a politically powerful daughter in law. She may overshadow the king’s role.
It is pretty common in the old ages where some men dont want women to have their own voices.
I dont understand why would the king be opposed to his top choice to be Empress being an esteemed doctor. In fact, it would work politically if the Crown not only had a skilled leader as the Emperor, but a knowledgable and practicing doctor as Empress. There are scholar-kings, and it shouldn't hurt to have scholar-queens.