Why enumeration comes from sitemaps here
A collector pointed at the search on this site comes back nearly empty and the usual conclusion is that the source is protected. It is not; it is simply built so that discovery happens through published sitemaps rather than through crawlable listing pages.
Reading the sitemap first turns a difficult crawl into a simple one, and the per-course sitemaps do more than list addresses - they describe what each course contains, which is exactly the material inventory a client wants and would otherwise have to assemble by walking pages.
The second reason this source is unusual is licensing. Most educational content is collectable for analysis and not reusable. Here reuse is frequently permitted, which makes it one of the few sources where a client can build something on the content itself rather than only on statistics about it. That makes recording the licence per course a functional requirement rather than a compliance gesture.
The third is curriculum research. Two decades of syllabi from one institution, with terms and years attached, is a record of how a curriculum changed - what was added, what stopped being taught, how a subject's reading list drifted. That question is hard to answer anywhere else with this consistency.
The fourth is scope. This is one university, and a strong one, which makes it excellent for depth and unrepresentative for anything claiming to describe higher education generally.