If there is an objection one may legitimately raise with the notion of "organic development of the liturgy," it is that upon close scrutiny the term is relatively confused. It sounds convenient. It encapsulates into wording the sentiments behind various contemporary opinions related to the Western liturgy. It does not necessarily denote much of anything substantive.
The crux of the problem appears when we separate out the words "organic development." The legitimacy ascribed to the concept of "organic development of the liturgy" in certain liturgical circles stems largely from the fact that "organic development" seems to have a quasi-scientific/quasi-sociological ring to it, thus lending an air of intellectual credibility to particular liturgical (and ecclesiological) positions in the Western Church, particularly within the Roman Patriarchate.
Yet, it is worth asking of purveyors of "organic development" really know what they mean to say. The closest parallel to "organic development" is "organic growth," both in terms of bio-chemical and business expansion.
Roughly, in the bio-chemical sense, organic development or growth refers to the maturation, mutation, and completion of the life-cycle of organic matter, though it may refer particularly to plants or animals. It presumes that as a result of the long evolutionary process, and at this particular stage of relative evolutionary stability, the various life forms that comprise the global ecosystem certain laws or processes of maturation, mutation, and consummation have been set as a result of an organism's bio-chemistry. There are certain patterns of maturation, mutation, and consummation that are encoded into our DNA/cell structure and the results of these patterns are to be expected. Forgive me for the crudeness of this description, but I think it conveys the concept.
In terms of business sense, organic development or growth would refer to expansion (in terms of size, transactions, and revenue) due to increased productivity, customer growth, and product. It runs contrary to growth by acquisition or merging, which oftentimes take a company away from its core purpose and ideals.
When one wants to qualify the phrase "organic development" with "of the liturgy," one should have a sense of what the phrase actually means. Its two primary meanings having been considered, it is difficult to see "organic development of the liturgy" as a muddled notion, more suited to codify a certain romanticism surrounding the Western Liturgy than actually describe a real historical process.
"Organic development of the liturgy" presumes that there are certain unstated laws governing liturgical change. There is almost a sense of liturgy as this other reality, this ethereal organism with its own internally coded structure that predictably yields expected patterns. Liturgical change always falls within the inner coherence of the liturgy, always producing certain patterns of change. Anything in violation of these patterns is a violation of the laws of growth.
Historically, it is almost impossible to find any recorded example demonstrating this theory has a factual basis in either observed behavior or written documentation. Was Pope Sergius' importation of the Sanctus from the Greek family of liturgies a move that was coherent with the internal logic of the Roman liturgy of the 8th century (as we can piece it together)? Did Alcuin follow the expected patterns of growth of the Roman liturgy when he supplemented the sparse Hadrianum with a generous stock of texts drawn from the storehouse of the Gallican liturgy, creating the basis of the "Traditional" liturgy as we know it? Or was this an example of merger and acquisition? What about revisions of rubrics or the abolition of ancient Mass sets and offices on the basis of recently created papal dogma? Does this follow with the predictable patterns of growth of the liturgy? If so, can we please have an example demonstrating that such prerogative is inherent in the Latin liturgical family?
"Organic development of the liturgy" would be better suited for liturgical studies if it jettisoned its inherent new-speak and settled on the meaning of "organic development." Then perhaps serious discussions can begin over two points raised by business and bio-chemistry 1) accounting for challenges to and opportunities for growth, and 2) entropy followed by decay.