At that particular time, there were far more studies being published. Of course, people had always known (sort of) about the history of the liturgy with liturgists like Dom Martene or Cardinal (St.) Tomassi. But at that time, new liturgical texts were discovered, new analyses were been made, and there was a greater interest and progress in other liturgical rites as well.
The impact of it all was profound. To digress for a moment: when I started reading different books about different aspects of the liturgy, it all seemed very strange and wonderful. One gets into the ideas of development, of thanksgiving, of symbolic action and so much more. When you look at the Traditional liturgy through that lens, it appears as a jumbled conglomerate of prayers shoved into pristine structure. A hodge-podge of ideas, no logical sequence, much repetition – you can find many faults.
And so, the ideas of one branch were simple: why do we need all these disfigurements, these multiple devotional prayers with their repeated ideas and confused theology? Why not get rid of all these “accretions of the centuries” and let the Roman rite shine in primitive simplicity that would also make it much more accessible?
One problem here, of course, is where do you stop? 7th century? 6th century? Hence some argue for a liturgy that does not exactly ‘time travel’ to another century but fits in with perceived modern ideas, and ‘liturgical principles’ and a certain form of theology.
This argument is in fact, still repeated today by many liturgists, who are not satisfied even with the NO. From that viewpoint, the liturgy has certain ‘clear outlines’ as it were.
1.Liturgy of the Word
2.Liturgy of the Eucharist
The main emphasis of (1) is Scripture. Thus nothing else should be given too much prominence. Lengthy ‘introductory rites’ should be avoided. Something short if you have to, but by all means after the psalm or song say the Collect (a.k.a. gathering prayer) and get on with the reading as quickly as possible. End with praying for people.
(2) Main focus here is the mantra “take, bless, break, give”. No Offertory texts only a simple Offertory procession that highlights the community offering gifts. The priest should merely prepare the elements i.e. ‘take’ but without prayers because the action should speak for itself. Then say an offering prayer, then move on to ‘blessing’ – say the Eucharistic Prayer. Communion rite- as short as possible. Only preparation should be the Our Father and Sign of Peace. Then we should ‘break’ – namely the Fraction – and then the Communion Rite should take place. Do not lengthen it with all manner of private prayers and Domine non sum dignus’s. Then say the Postcommunion thanksgiving prayer, and dismiss the people.
Of course, I do not say that everyone then was inspired by Dix’s “fourfold action”, as many seem to be now. Far from it. Some preferred the structure for its easier and hence-supposedly more ‘pastoral’ nature. Others, as I wrote previously, simply wished a return to the pristine age of the Roman liturgy free, from all obscuring “accretions”. Some wanted certain parts changed in a more logical fashion. Even within the revisers, and the promoters of reform there were disagreements – how long should the Eucharistic Prayer be, should it include this much petitonary material, should we model it on a thanksgiving, should there be a final blessing, etc., etc.
Another central idea is that the liturgy should be somewhat ‘fluid’ in accommodating itself to various types of peoples and situations. One place where it was felt was in the rubrics which were(and still largely are) not so minute as in the Traditional Missal. In its worst form, this has led to all manner of abominations and abuses. In another form, it explains why the NO provides so many options at the discretion of the priest-celebrant, options for different communities, or why it lends itself to cultural adaptation, or why it provides (or provided, in some areas) places for monitions by the celebrant. The Jesuit Fr. Tihon, wrote in Nouvelle Revue Theologique, in 1965, when changes were just coming how”
If exact specifications no longer dictate the manner of making such or such a gesture, this is not for the simple purpose of loosening the iron collar of the rubrics; it is a question, above all, of affording the celebrant an opportunity for genuine self-expression, that is to say, an expression that is vital and personal, appropriate for eliciting community response and prayer
Again consider this portion of an article on liturgical changes:
Liturgy exists as a function of the people of God. It follows that liturgical rites have no intrinsic or inherent value. They must be evaluated in their relationship to the people of God from whom they derive their meaning. Thus rites have a relative and dependent value. They are valuable to the degree that they express the nature and disposition of the assembled congregation. Further, if this expression is to be at all representative of a given community, control of the liturgical forms must to a considerable extent be the responsibility of the local pastor and his flock
You can almost seen in some of this why we have Eucharistic Prayers for Reconciliation, or the ‘Swiss Canon’ prayers. It is the reason why dropping of other elements of the Traditional Mass was justified – they didn’t possess the same sign value as they once did (how exactly that was decided is another thing….).
This is also the second impetus that governs much of the reform of texts. The texts, it was felt, must speak to the modern conditions, they must be at once theological, instructive and pastoral, and they should be based on a sense of the liturgical year. Thus we witness the rearranging or omissions of various variable prayers of the Mass. The same is true for the other rites e.g. the gloom-and-doom mediaeval emphasis of the funeral rites must be replaced with a hopeful, resurrection-style text.