What drives changes in writing course curriculum?

I am doing the first phase of a project on the history of a first year writing course. It's mostly document analysis of the founding documents of the course (recommendations from a curriculum committee, a proposal for the course, and ten years of syllabi of the course). The next phase will involve interviews with the people responsible for the syllabi (I hope).

I haven't found much in the literature on this -- historical studies of university writing courses, but I'm sure there must exist something like this out there -- and I find it fascinating.

When I started the project I proposed that it would be about the pedagogical, theoretical, and disciplinary influences on the way the course has changed its teaching and assessment methods over the years.

I was told again and again, though, that this didn't make sense because the idea that these things are the primary drivers of change is misguided. At first I didn't get it, or refused to go along with this idea. I still think that the way someone is trained, or the ideologies they bring with them about writing or teaching or language (which in academia are shaped in part by what disciplinary communities you align yourself with -- who you read) matter a lot when it comes to how the teaching of writing is actually carried out, and I probably will get to this eventually.

But now that I've been working (properly working, not as a grad student) at a university for about a year, I am starting to understand this. This must be incredibly obvious to anyone with more experience than I have, but I see now that:

Local and institutional social/political/ideological factors drive curriculum/ pedagogy/assessment more than "current theory and research" in a discipline drive these things -- for a few reasons, but mostly because the people at the top who make the decisions have different ideas and priorities than the people at the bottom who actually work with students.

This doesn't only affect how we teach and assess, etc (though this is important and something I need to learn more about for my project), but it affects who is teaching and assessing etc, and this is important I think.

At my own institution (well before my time) there have been administrative decisions which resulted in, among other things, the dissolution of a writing center, the creation of two subsequent writing-focused units that folded into other units and eventually disappeared, the implementation of a writing-intensive learning initiative which gradually lost its administrative infrastructure but still remains on the books, the re-emergence of student writing services in a new unit, and the establishment of an English-language support-focused unit (which seems to be part of a shift in the discourse I'm seeing across certainly my own geographical context if not more widely, from universities perceiving a need for 'writing support' to 'language support,' which is mostly a good thing but brings of some interesting and contentious issues when it comes to disciplinary divisions of labour).

All or most these decisions resulted in people being hired or losing their jobs, in instructors getting or not getting help doing their jobs, in students having or not having access to more help with their writing. In other words, these decisions added and subtracted people who bring with them all the stuff I talked about in the 4th paragraph above.

Anyhoo...more on this later, I hope.