“The so-called explanation is that calling Mary the mother of Jesus’ body puts her above him.”
No. The original inferred statement was:
‘Mary is the Mother of the Body of Christ.’
Now I can tell you understand where I am coming from by your act of not confronting the actual claim, and instead making a strawman in its place.
In the Catholic Church we believe what the bible says about how Christians are members of the one body whose head is Christ.
And we believe what the Bible says about how Mary gave birth to the Christ.
So we believe that the mother of the head is mother of the body.
And so we believe that Mary is our mother, since we are members of the Body whose head is Christ.
Non-Catholics find the Bible hard to believe.