But while I was looking, I did find this, where Cardinal Ratzinger alludes to the fact that we could have the TLM in the vernacular:
latinmassjax.org/augustnewsletter.htm
This part from your link is quite interesting. The response from Pope Benedict then Card.-- to Doctor Barth.
Very honored Doctor Barth!
Heartfelt thanks for your letter of April 6th, the response to which I only now find the time to make.
You ask that I involve myself in the wider authorization of the old Roman Rite. You yourself already know that for my part, such a request does not fall on deaf ears; indeed, my involvement in this wish has, as it happens, become generally known.
"However, whether the Holy See “will once again worldwide and without limit authorize” the old rite as you wish it and have heard through rumor may happen, cannot be simply said or entirely confirmed.
One must always reckon with the fact that too many Catholics have been
inoculated for years with an aversion to the traditional liturgy, which they disdainfully call “pre-conciliar” and likewise with considerable opposition on the part of many bishops against a general reauthorization [of the old rite].
Commentary: Here Cardinal Ratzinger states a problem or hindrance with granting a widespread and unlimited authorization of the use of the Traditional Latin Mass: too many laity have an aversion to this Mass and many bishops are opposed. Ratzinger deliberately uses the word “inoculated”, implying that the action of sowing hatred for the TLM is both deliberate and systemic. He does not say by whom this has been done, but simple
research indicates it starts with the Roman Curia itself and spreads by means of national bishops’ conferences
right down to the parish level. Likewise, “inoculated” indicates that the Catholic laity and bishops willingly
stood up and accepted the poisonous disinformation worldwide. This is the penalty we have imposed on ourselves for not taking responsibility to learn our Faith and our holy Tradition, and for not taking the time to learn and understand the history of our Sacred Liturgy.