It is you that does not understand that the Lord's humanity is not secured through Mary if she is not fully human as ourselves. That you continuously give her attributes that make her less then the human vessel that God intended her to be is what is not Scriptural.
Moses could not wear his sandals on the ground near the burning bush because it was Holy, the site of a Theophany.
Yet the apostles and the Lord's disciples walked with Him, ate with Him, and learned at His feet. There is no parity here for the two situations. The Lord walked among us fully human, yet fully divine. The humanity through the miracle of His birth, His Divinity through His Sonship with the Father.
The view being objected to is the view that the Mother of our Lord was somehow a piece of meat, who was at one moment the Spouse of the Holy Spirit, and at another moment engaging in completely unfruitful sexual relations that produced no children.
I certainly do not believe that the marriage with Joseph was unfruitful. He took her as his wife. Sorry you view the marriage condition with such low regard.