...because it is not an official teaching of the Church. Duh.
Although it is not 'yet' in the catechism, it definately is a teaching of your church...
Because YOU say so?
ROFLMAO
>>>Because YOU say so?<<<
Nope...Because the people that run your church say so...
~~~~~~~At the most recent Mariological Congress held at Czestochowa, 18-24 August 1996, a Commission was established in response to a request by the Holy See, which had asked to know the opinion of the scholars present at the Congress on the possibility and the opportuneness of defining a new dogma of faith regarding Mary as Coredemptrix, Mediatrix and Advocate. In recent years, the Holy Father and various Dicasteries of the Holy See have received petitions requesting such a definition.~~~~~
http://www.accademiamariana.org/archivio/pami/page8.html
~~~~~The universal mediation of the Mother of Jesus as Coredemptrix, Mediatrix of all graces, and Advocate for the people of God is already contained in the official and authoritative teachings of the Church’s Magisterium. Now, at the summit of the Marian era, what remains is the final proclamation by the Church of this final Marian doctrine as Christian dogma revealed by God.~~~~~
http://www.ewtn.com/library/MARY/MEDIATRI.HTM
There’s tons of material on this subject...Seems some are a bit selective on the information you provide on the subject...